Towards learning to play guitar

I have started learning chords. It is hard, since almost nothing I know relating to music (or dance, for that matter) lives in my explicit memory. Chords names, unfortunately, must. I'm also trying to learn my way around my instrument a little -- scales (so far only the major scale) and just playing around with random tunes by ear, and... well... actually trying to remember what note each string is (this information refuses to stay in my brain for some reason... I guess because I never use it :|).

Up until now, all I've done is basically trained my muscles to produce a handful of songs, generally using tabs as instructions. (Even the song that I managed to figure out by ear: I wrote each bit down in tab form as I figured it out, and then learned each section using my crappy tab-like notes.) This, to me, has very little relation to knowing how to play an instrument. I want to be able to play a new song given a set of chord names, and I want to be able to improvise a melody over some set of chords being played.

So these two endeavours, learning names for things and learning my way around my instrument, are my current strategy for trying to learn how to actually play. I think part of the reason I never worked at either of these things before is that there are no discrete tasks with immediate payoffs at the end, as is the case with trying to learn individual songs. But now I am determined! By the end of the summer, I want to have considerably improved on both fronts. I just wish there was some good way to quantify and track my progress. :|