I've read some 60+ books on trading so far, and I can tell you the most they'll give you is insight on psychology, and money & risk management. Nothing about how to trade.

But if you're just looking to learn up on various instruments, markets, techniques, and vehicles, then the free stuff on the internet is entirely sufficient. I've found big batches of 400+ books myself for "free" just sniffing around. You might want to start with that.