Beginner

A poker beginner faces challenges that beginners in other hobbies may not face. The biggest of these is the simple fact that valuable practice costs money! Play money poker may serve a limited purpose, but to really get initiated into learning poker you'll have to put in time in real money games -- preferably starting at small stakes.

Wiki road map for beginners

 * Beginners FAQ - This should be your first stop, particularly before asking for help on rec.gambling.poker or Two Plus Two.  Those forums are generally full of people willing to help, but doing your part to read the FAQ will make it easier for them to focus on helping you with questions that don't have a simple answer.
 * Then you should pick a single variant in which to specialize as you start out.  Limit hold 'em and no-limit hold 'em are the two most popular variants by far, but you may also choose to play some less popular variant.   Omaha and seven-card stud, in both their high only and hi/lo 8-or-better variations, are quite popular both in brick-and-mortar and online cardrooms.   Keep in mind that wider game selection means greater profitability!   Your next few stops will depend on your choice of variant.

Knowledge you should acquire

 * How to count outs
 * Simple outs to odds conversion
 * Knowing when to discount outs that may not be to the unique best hand
 * Understanding of implied odds
 * Proper bankroll management
 * Knowing which hands beat which
 * Understanding the power of position in poker

Limit hold 'em

 * MicroLimitLibrary

No-limit hold 'em

 * Understand big draws and when you don't mind being all-in with them (see Phil Gordon's Little Green Book)