How to build a repertoire?

I'm a pretty average strength player, below tournament level I think but above novice. I've not really studied openings at all except looking up very specific traps I'd fallen into. Usually I can navigate the opening without any huge losses, but I don't feel like I'm really "in control" of how the position is going to play out.

 I stick to e4 usually, and with black try to set up a center pawn firmly on fith rank. So I have standard replies that I usually make, and it works ok for me but probably not optimal. Should I devote much time to memorizing opening variations and stuff or is study better spent on the more fundamental endgame concepts?

Or to put it more plainly, how does one go about building a "repertoire" when there are so many thousands of possible moves? What exactly constitutes a servicable repertoire for an intermediate level player?

 I just sent you an answer to this on your other post, Non improvement

You ask 2 different questions :

1) Should I devote time to build an opening repertoire ? 

Well, it's certainly very useful if you're already an intermediate player, but it depends also on your personal tastes : if you enjoy other parts of chess, you don't have to build an opening repertoire now - some players do it late

2) How do I do it ?

There are many ways, but it's probably easier to start from an existing repertoire and then adapt it to your preferences :

- either you model a player in your local club and learn his set of openings - this way, he can explain and help you analyze your games

- or you can buy a 'repertoire book' on the market - there are plenty of them

- you can model a player you know - pick his openings and try to play them

- or you can pick openings you feel attracted to, for one reason or another, and start building from there...

I can give more specific advice if you have other questions, but you have to know that building a repertoire takes time (many many years), so you need patience

yoshtodd> Or to put it more plainly, how does one go about building a "repertoire" when there are so many thousands of possible moves?

There may be thousands of moves, but a solid, tournament-level repertoire only needs to focus on strong and popular moves. If your opponent makes a weak, uncommon move it's ok to spend a little clock time refuting it.

(Note: if you are not able to refute weak moves when you have time to do so, you probably need to study general opening principles from a book like Improve Your Opening Play or The Ideas Behind the Chess openings.)

Now, the question is which openings to learn? 1 white and 2 black openings are a good place to begin (later you may add additional lines to use in must-win situations or as surprises or more efficient ways to handle unusual openings). It will simplify your study if you choose openings with some similarity--for example, the Slav and Caro-kann have similar pawn structures, as do the English and Sicilian. You also want to pick an opening that's in-line with your playing style--do you like wild tactics, slow positional play, etc. 

(Note: If you don't know a bit about all the openings, again a book like Improve your Opening Play or The Ideas Behind the Chess Openings is useful.)

Once you've chose your openings, how to learn them? You want to learn THEMES and MIDDLEGAME PLANS and TRAPS comon to that opening. One way to do this is to study annotated master games in your opening lines--that's what most opening books contain. Next, you need lots of practice to get comfortable with it, and that's where blitz games come in handy. Finally, you can memorize lines using tools like Chess Opening Wizard and keep up to date using tools like Chessbase, Informant, New in Chess, or TWIC.

Good luck. And again remember, trying to memorize thousands of lines is going to be absolutely the wrong approach for most people and openings. And it is possible to put together a basic repertoire in a few months--just pick less theoretical lines.