AlexCox.com--They're nearly all there--"Repo Man," "Sid & Nancy," "Walker," "Straight to Hell" ("More COFFEE!"),"Death and the Compass," and even a couple written by Peckinpah-scribe Rudy Wurlitzer (one co-written with Cox). FREE. Just download them, print them, and read them.
Aspiring screenwriters could learn a few tricks. Reading screenplays is a good start, and aids in understanding the conventions of screen-writing. Starting with Mr. Cox's texts is a good place as any to begin. With a crashing world economy, FREE is as good as it gets!