What is an efficient way to train one's self at Chess?
I really enjoy playing, perhaps 1-2 times per week. I used to play on an electronic board once per day and at one point I could start to beat it on a regular basis. However, I find it extremely hard to improve myself, and the literature is vast.
If I would like to get to the next level, what is a reasonable approach? Just continue playing, or is there a more systematic approach? Starting to memorize openings? Maybe that's overkill and there could be other things I might do first. I've just glimpsed into Bobby Fischer Teaches Chess, looks like reasonably leveled book. Any other suggestions?