Your best examples of the stream of consciousness technique will come from the first two sections: Benjy's and Quentin's. Benjy is mentally challenged, and as such he has no true concept of time. Present developments trigger past memories. Accounts of Caddy's climbing the tree, her wedding, Benjy's name change, Quentin and Caddy fighting as children are interspersed with the present developments of golfers golfing and Luster hunting for his money in the grass. The passages in italics would be good places to begin to search for examples.
Quentin's section is no less difficult for the reader. Quentin is a Harvard student, clearly intelligent, and unlike Benjy, very aware of time. But his mind also races from past to present and back again, as this section records Quentin's thoughts a day before his suicide. If you turn to this section, you will have no trouble finding examples of references to time, past, present, and his obsession with Caddy. Quentin is clearly unbalanced, and Faulkner's style represents this mental instability. Places to look in this section for examples are the lengthy paragraphs and italics that often contain Quentin's recollections of conversations he has had with his father--mainly Quentin's attempts to prevent Caddy's marriage-- and with his mother. At the heart of this section, though, are Quentins' conversations with Caddy that are recounted in short phrases without quotation marks or punctuation of any kind, for that matter, echoing Quentin's recollection of their discussion of Caddy's sexual activities.
Faulkner’s novelistic style is considered high modernism, which is to say that he, like many of his contemporaries, tried to change or challenge or understanding of space and time. Modernists felt that the traditional method of presenting space and time in the arts didn’t mesh with how we experience life. Life is a blend of sensation, memory, emotion and thought all rolled into an indivisible experience. One technique modernist novelists used to present the indivisible experience of life was stream of consciousness.
Stream of consciousness was a technique where the writer tried to present the story in the way that the narrator’s experiences, including the random sensations, memories, and emotions they have during a particular event, are presented in the illogical jumble that the character would have experienced them. The presentation of these pieces are woven together the way they are in real life.
For example, the baseball game that the narrator is watching is interrupted by a memory that it triggers and perhaps the sensation of being cold. Then the car down the street backfires, triggering a new set of sensations and memories that disrupt the flow of the baseball game. The result is that the reader may not be able to follow the activity of the event clearly because they are interrupted in their understanding.