NLH has three basic things will continue to come up over time you study and play poker.
Your position at the table (Position), the hands you decide to play (Selection), and the actions you should take while playing each hand (Aggression).
With that, I have a P.S.A. to make:
Attention! This is a Public Service Announcement to let you know if you want to get better at poker you need to learn about Position Selection Aggression.
Poker Moves
The Triple Threat - Evan Jarvis (Gripsed Poker Strategy)