To get started, I'd suggest the following four books:
The Intelligent Investor by Graham
Common Stocks and Uncommon Profits by Fisher
Why Stocks Go Up and Down By Pike
Buffettology by Buffett and Clark
If you read these books thoroughly and in that order and
never touch another book, you'll have all you need to know.
Another book you might want to consider is Value Investing
Made Easy by Janet Lowe - a quick read. I have
a fairly extensive listing of books on my site, with my
reviews of them, and links to purchase them at amazon.
My problem is I've read way too much. One book stated, "If
you're not a voracious reader, you'll probably never be
a great investor." But sometimes I wish I had a more
focused knowledge base so that my investment strategy wouldn't
get all cluttered up.
Re: Security Analysis you can get a lot of the same info
in a more accessible format elsewhere, but everyone says
that Buffett's favorite version is the 1951 edition. Yes
there are differences, and the current version has a lot
of non-Graham like stuff in it.