Blackjack Bluebook II by Renzey: good to learn from, easy reading
Blackjack Blueprint by Blaine: a tutorial for BS and Hi/Lo, plus advanced topics
Blackjack for Blood by Carlson: good to learn from, interesting anecdotes
Blackbelt in Blackjack by Snyder: a complete textbook on BJ
Professional Blackjack by Wong: the single, best source for Hi/Lo count, lots of tables
Million Dollar Blackjack by Uston: interesting read, both technical and anecdotal
Eventually you should read them all, but 3 will do for starters.
BJinNJ