I've played chess for about a year, and I think I'm a pretty good player. However, I've noticed there's one thing I need to do - memorize some opening lines and variations and know what moves to make to get an advantage.
Knowing good defenses as Black is necessary for progress. What should I play against 1. e4 ? If I were to play a certain opening, how should I play - aggressively, or calmly? Should I try to open or close the position?
How can I get an advantage while still knowing what I'm doing? Please give me a few openings I can study, and perhaps the ideas behind the moves? (Just memorizing moves is useless.)