The concluding section of John 1 deals with the calling of the disciples: John attests to Jesus' status and two of his followers defect to Jesus. They in turn spread the word, and Peter is given his name.
I thought though it would be particularly useful to focus in on the calling of Nathaniel (45-51), firstly because it introduces the figure of the fig-tree which is a recurring motif through the Gospels. But also because it is the subject of an interesting and useful analysis of correct and modernist approaches to Bible interpretation in a series over at the Roman Theological Forum.
First the text.
35 Altera die iterum stabat Joannes, et ex discipulis ejus duo. 36 Et respiciens Jesum ambulantem, dicit: Ecce agnus Dei. 37 Et audierunt eum duo discipuli loquentem, et secuti sunt Jesum. 38 Conversus autem Jesus, et videns eos sequentes se, dicit eis: Quid quæritis? Qui dixerunt ei: Rabbi (quod dicitur interpretatum Magister), ubi habitas? 39 Dicit eis: Venite et videte. Venerunt, et viderunt ubi maneret, et apud eum manserunt die illo: hora autem erat quasi decima. 40 Erat autem Andreas, frater Simonis Petri, unus ex duobus qui audierant a Joanne, et secuti fuerant eum. 41 Invenit hic primum fratrem suum Simonem, et dicit ei: Invenimus Messiam (quod est interpretatum Christus). 42 Et adduxit eum ad Jesum. Intuitus autem eum Jesus, dixit: Tu es Simon, filius Jona; tu vocaberis Cephas, quod interpretatur Petrus. 43 In crastinum voluit exire in Galilæam, et invenit Philippum. Et dicit ei Jesus: Sequere me. 44 Erat autem Philippus a Bethsaida, civitate Andreæ et Petri.45 Invenit Philippus Nathanaël, et dicit ei: Quem scripsit Moyses in lege, et prophetæ, invenimus Jesum filium Joseph a Nazareth. 46 Et dixit ei Nathanaël: A Nazareth potest aliquid boni esse? Dicit ei Philippus: Veni et vide. 47 Vidit Jesus Nathanaël venientem ad se, et dicit de eo: Ecce vere Israëlita, in quo dolus non est. 48 Dicit ei Nathanaël: Unde me nosti? Respondit Jesus, et dixit ei: Priusquam te Philippus vocavit, cum esses sub ficu, vidi te. 49 Respondit ei Nathanaël, et ait: Rabbi, tu es Filius Dei, tu es rex Israël. 50 Respondit Jesus, et dixit ei: Quia dixi tibi: Vidi te sub ficu, credis; majus his videbis. 51 Et dicit ei: Amen, amen dico vobis, videbitis cælum apertum, et angelos Dei ascendentes, et descendentes supra Filium hominis.
You can find the Greek, Latin and Knox translation here, and listen here from 3.48 for the Latin, and the Greek from 4.14.
And the English (Douay-Rheims, for a more literal approach to the Latin than the Knox):
 The next day again John stood, and two of his disciples. And beholding Jesus walking, he saith: Behold the Lamb of God.  And the two disciples heard him speak, and they followed Jesus.  And Jesus turning, and seeing them following him, saith to them: What seek you? Who said to him, Rabbi, (which is to say, being interpreted, Master,) where dwellest thou?  He saith to them: Come and see. They came, and saw where he abode, and they stayed with him that day: now it was about the tenth hour.  And Andrew, the brother of Simon Peter, was one of the two who had heard of John, and followed him.  He findeth first his brother Simon, and saith to him: We have found the Messias, which is, being interpreted, the Christ.  And he brought him to Jesus. And Jesus looking upon him, said: Thou art Simon the son of Jona: thou shalt be called Cephas, which is interpreted Peter.  On the following day, he would go forth into Galilee, and he findeth Philip. And Jesus saith to him: Follow me.  Now Philip was of Bethsaida, the city of Andrew and Peter.  Philip findeth Nathanael, and saith to him: We have found him of whom Moses in the law, and the prophets did write, Jesus the son of Joseph of Nazareth.  And Nathanael said to him: Can any thing of good come from Nazareth? Philip saith to him: Come and see.  Jesus saw Nathanael coming to him: and he saith of him: Behold an Israelite indeed, in whom there is no guile.  Nathanael saith to him: Whence knowest thou me? Jesus answered, and said to him: Before that Philip called thee, when thou wast under the fig tree, I saw thee.  Nathanael answered him, and said: Rabbi, thou art the Son of God, thou art the King of Israel.  Jesus answered, and said to him: Because I said unto thee, I saw thee under the fig tree, thou believest: greater things than these shalt thou see.  And he saith to him: Amen, amen I say to you, you shall see the heaven opened, and the angels of God ascending and descending upon the Son of man.
John McCarthy's notes on these verses over at the Roman Theological Forum's study course provide a dissection of historico-critical approaches to these verses and the errors they involve. He then suggests that the better approach is neo-Patristic:
"...All of the Fathers of the Church understood the passage about the calling of Nathanael to be an exact historical description of what actually took place...it is necessary to realize what is hinted at in the text, namely, that Philip and Nathanael had some knowledge of the Scriptures, and that part of this knowledge had to do with the origins of names. Now it was easy for Nathanael to conjecture on the spur of the moment that the name Nazareth comes from the Hebrew verb nazar, meaning "to set apart,""to consecrate," and, therefore, "to make holy." So Nathanael made a witty remark, "Can anything good come from Nazareth?" meaning "Can anything good come from the town named holy?" This was only a facetious remark, but it did cast a humorous aspersion on the origin of Jesus. Now, Jesus outdid the wit of Nathanael as He quipped: "Behold a true Israelite in whom there is no guile," for Nathanael knew that Israel, that is, the Patriarch Jacob, was one of the most guileful persons who ever lived, and this witty and ironical riposte of Jesus caught Nathanael in his own conceit. Surprised by this spirited opening of Jesus, Nathanael asks: "From where do you know me?" - thus bringing up the question of origins, and Jesus refers to the origin of Nathanael as He replies: "I saw you when you were under the fig tree." A contemporary writer has noted that Jesus must have been referring to some previous occasion, since fig trees were not in foliage at that time of year, but St. Augustine long ago suggested the answer, when he said: "Adam and Eve, after sinning, made themselves aprons of fig leaves. Fig leaves, then, signify sins, and Nathanael, when he was under the fig tree, was under the shadow of death." So, on the level of the literal and historical sense, the implication of this observation of Jesus is that Jesus saw Nathanael when he was still in the seed of his first parents Adam and Eve, who stood shamefully under the fig tree after their sin. Thus, in answer to Nathanael's quip, "Can anything good come from Nazareth? Jesus replies in effect: "You joked about my supposed place of origin, but I saw you when you were still in the seed of your first-parents Adam and Eve, as they stood naked and ashamed under the fig tree." Nathanael, aided by grace, understands this, and he exclaims: "Master, you are the Son of God; you are the King of Israel." Nathanael probably intended the title "Son of God" in a human rather than in a Trinitarian or Incarnational sense,15 but he did thereby correct his witty remark and attribute to Jesus the highest and holiest of origins, being the son of the most holy God and having the social status of a king. Jesus approves this insight and then elevates it as he turns to the group of his disciples and says: "You shall see Heaven opened and the angels of God ascending and descending upon the Son of Man." When would they see Heaven opened? Ultimately and completely after their death when they would be accorded the Beatific Vision. In Heaven they would see the good angels ascending in thought and in prayer to the divinity of Jesus and descending in service upon his humanity, to which He is specifically referring when He calls Himself the Son of Man. The Heaven to which we refer is, then, not a religious fantasy; it is the ultimate reality attainable by man."
"...On the level of the lower allegory, that is, the Allegory of Christ and his Church, Jesus is "from Nazareth" in the sense that his human nature was conceived virginally "from the root" (netser) of Jesse and David in the womb of the Blessed Virgin Mary. And the humanity of Jesus is the Ladder of Jacob, the bridge between earth and Heaven. On the level of the higher allegory, that is, the anagogy of the Trinity and of the Four Last Things, the reference to "heaven opened and the angels of God ascending and descending upon the Son of Man" is the literal and historical meaning of the words, to the extent that this is one of the texts which literally underpin allegorical references to Heaven elsewhere in Sacred Scripture. Also on the level of the allegory of words, Jesus is the Son of Joseph, that is, the Son of the "Increaser", in that He is the Son of God the Father, who is the absolute Increaser of all things. On the level of tropology, the moral allegory, Nathanael accepts the invitation to "come and see," and, over and above his geographical journey to Jesus, he has an experience of conversion from conceitedness over his birth and his academic education to an awareness of the lowliness of his human birth and the highness of the birth of Jesus, the Messiah. So Nathanael becomes a follower of Jesus. His exchange of irony with Jesus is like his forebear Jacob's wrestling with an angel: but Nathanael comes away with only his pride wounded and he walks thereafter in humility, as he also receives the blessing of a promise of eternal life. And his guile is no longer personal conceit, but rather a growing understanding of the deeper meaning of divine revelation and an increasing love for Jesus, the Bridegroom of souls."
You can find the next set of notes, on John 2:1-12, here.