I also recommend Bob Bly and John Caples. Another good copywriting book is "Cash Copy: How To Offer Your Products And Services So Your Prospects Buy Them...NOW!" by Jeffrey Lant.
http://www.jeffreylant.com
For web copywriting, you can download this free e-book at my website - "14-Point Web Copy Analysis Of A
Winning Site." Yanik Silver walks you through a webpage and gives details on why the copy is effective.
Get FREE E-books, resources, tips, copywriting, articles, and Keyword Sleuth at
http://www.dc-infobiz.com