Welcome to the Forums.
Pokerstars do a decent job of explaining basic rules etc to a complete beginner on their
poker games pages.
If you want a book,
Getting Started in Hold'em by Ed Miller is recommended. (OK, Hold'em isn't the only poker game, but you could pick worse ones to start with.)
The stickies and FAQ on this, Beginners, Forum are full of useful info but if you don't yet know basic game play, I'd suggest the Stars stuff first.
Good Luck
