Ugly Moves

How does one improve chess skill?

I've been pondering over it the last few days.

When one looks at chess position OTB, how does one know instinctively if a move is good, bad, could be better? In chess, the common problem with patzers like me is that I tend to make average moves. Even worse, in a complicated tactical position, I have a problem of either:

a. Not calculating variations deep enough
b. Being oblivious to my opponent's threats

The answer unfortunately, that I have arrived is that I need to do more tactics. If I have tactics down pat, I should be able to logically figure out what moves are optimal and what moves are not. I am currently looking for a couple of Chess Books/CDs/DVDs that are not just 1-2 moves but 4+ moves to in order to improve my tactical skill (or as some people like to call it, chess "eye").

I am quite frankly tempted to shell out some money to get some help (I can't afford a chess coach) rather than working on blindly with no direction whatsoever. Reinfeld's 1,001 Combinations is fine and one can blitz through it in record time because of the 1,2,3 move combinations that stick out in your face at once but I need something more in-depth. I am well open to suggestions at this point in time to anything.

On a sidenote, with my finals coming up soon near the end of October, I can afford precious little time (not to mention, I need to concentrate more on my 2 exams this week *yikes*) to concentrate on chess studies.