From the United States Conference of Catholic Bishops -
In the procession to the altar, in the absence of a Deacon, the reader, wearing approved attire [see GIRM, no. 339], may carry the Book of the Gospels, slightly elevated. In that case, the reader walks in front of the Priest but otherwise walks along with the other ministers.
Upon reaching the altar, the reader makes a profound bow with the others [see also GIRM, no. 274]. If he is carrying the Book of the Gospels, he approaches the altar and places the Book of the Gospels upon it. Then the reader takes his own place in the sanctuary with the other ministers. (GIRM, nos. 194-195)
The reader reads from the ambo the readings that precede the Gospel. In the absence of a psalmist, the reader may also proclaim the Responsorial Psalm after the First Reading.
In the absence of a Deacon, the reader, after the introduction by the Priest, may announce the intentions of the Universal Prayer from the ambo.
If there is no singing at the Entrance or at Communion and the antiphons given in the Missal are not recited by the faithful, the reader may read them at an appropriate time (cf. nos. 48, 87). (GIRM, nos. 196-198)
At the conclusion of the Mass, the lector does not process with the Book of the Gospels. The Lectionary is never carried in procession. The lector may join in the procession at the end of Mass in the same order as in the procession to the altar.