Advice/Info on card counting?

I am wanting to learn everything I can about card counting. I have found a couple card counting tutors on the net but neither of them worked on my computer. If anyone knows any good sites that explain card counting thoroughly or card counting tutors/simulators that help you learn please let me know. Also if there are any better free blackjack games on the net than yahoo games, like one that is more realistic, please let me know if you have any info or anything.