First and foremost, don't trust any of the videos on youtube from expert village or livestong.com. The advice I've gotten from them seems to be in direct contradiction to what I've been taught in my classes.
Here is a good site that I found that discusses swimming technique. I got a lot of help from my swimming instructor this last semester with my strokes, and everything on this site seems to coincide well with what she's taught me when I need to review:
Also if you're just starting to use swimming as a work-out method, I recommend getting a kick board and a pull buoy if your gym doesn't provide them. Why? because they're a good way to practice the arms and kicks as separate pieces before combining them into the stroke. Trust me, it works and it's awesome.
Also in my case I can kick forever, so I'll do 20 minutes of kicking to start off my workout to ensure I'm getting in a good aerobics session along with practicing my stroke.