General considerations
With all the aspects of successful poker play presented on this website, it may seem difficult to be able to sort out which strategy one should use against which kind of opponent and under what circumstances.
This is the reason why, in order to really understand how successful poker works, you need to see the picture as a whole. Knowing about the different pieces of the puzzle will do little to help you, you’ll only truly know what there is going on at the poker table when you understand the nature of the game, and see all the different bits and pieces as part of a whole. Piece together the puzzle and you’ll have a revelation: you’ll not only realize that online poker is indeed beatable in the long-run, you’ll also understand why, and you’ll hopefully see how you have to get there too.
Starting hand selection, preflop betting, the different actions you’ll take in different stages of a poker hand (flop, turn, river) will come together with the edges you can secure away from the table, like rakeback and table selection, and other factors like the ability to read your opponents and draw conclusions based on their betting patterns.
Keep in mind that, while much like a general, you need to win the war, not any individual little battle, you cannot afford to neglect any one of these battles, no matter how tiny they may be. As in war, where the most resourceful combatant emerges victorious, so shall in poker, the player who pays the most attention to every minute detail, beat his/her opponents as well as the rake, at the end of the day.