Decide which one of the many and varied poker games
you would like to play.
Hold'em is one of the most popular games and is relatively easy to learn, and it is played both in card rooms and on the internet.
Buy a good book to teach you the rules of the game and its basic principles.
Completely understand what is written. To start with play only strong starting hands in low limit cash games.
Beware of freerolls
on the internet lest you fall into other player's bad habits. Players develop a "play any two cards" mentality. Once in a hand will play No Fold'em Hold'em and call to the river.