I completely agree with the above (and I used to do professional video production). Plan, light and frame your shots properly. You don't need to go out and buy yourself a several-thousand dollar camera to get good results. I've seen some amazing stuff done with phone cameras and GoPro's.
Apart from the visual aspect, give your audio strong consideration. If you're doing indoor close-ups or "talking heads" shots, get yourself a decent lapel mic (it doesn't have to be wireless although this does come in very handy if you're moving around). Alternatively, I'd be looking at a basic shotgun microphone which you can mount on a tripod either behind the camera or out-of-shot above your head. The
RØDE NTG-series microphones are very good. Set your gain levels so unwanted noises such as anything in the background or you breathing/moving about isn't captured.
If you're doing voice-over work, you can get away with the shotgun at a pinch, but I'd be looking at a decent condenser or dynamic microphone for those, again, RØDE make some excellent gear but Shure, Sennheiser etc... are just as good. Even just a Shure SM58 microphone will sound excellent (they go for well under AUD$200).
Bad audio is just as annoying to the viewer as bad video.
Just make sure whatever you buy is from a reputable reseller. Believe it or not there are a lot of Chinese fakes out there and they are absolute rubbish (as you'd expect).
EDIT: Dave
just beat me to the post. What he said.