Poker is a game mixing luck and skill. Any player can (even if he plays randomly), be a winner on the short run. On the short run, the impact of luck is really huge (more than skill)! (when i have some time, i will write an article on that subject). On the contrary, only those who have begun to understand the mechanics and dynamics of the game will show a profit on the long run.
This section will provide articles dealing with the tools and the state of mind that every serious poker player have to know. I'll publish a few poker books reviews too.
These articles require that you already know the rules of open poker (available here).

Expected value, pot odds, implied odds...(Beginner/Intermediate)
When should you move up? Estimate your skill. Manage your bankroll.(Intermediate)