I would invest in some good heads if I did nothing else. If you're using your original heads they will probably make for an out of tune and weak recording. Remo makes a nice rock pack set for 69.99...I'm partial to Evan's coated snare heads though.
I record using a presonus firepod. It has 8 inputs, so I can record each mic as a separate track. This is awesome because I don't have the most expensive set either, but with each mic on a separate track you can add effects specific for each. With adobe audition there are several effects for bass drums, snare, cymbals, etc. If you use a mixer before your recorder you're going to only have 1 track, and any effects you add will be added to everything.