1) insulation and absorbing material is very important concerning frequencys, especially the low end downwards 300hz.( bass traps).
To get recordings and mixing right, this is the basic rule.
2) about software, if your main concern is live recording I would suggest to use cubase sx or nuendo.They both have powerfull audio engines and wave editing possibilitys.
3) the soundcard should have 4 inputs because , when recording drums properly use 4 mics.( Kick-snare- and two overheads, cymbals and Hihat)
4) a very good recording system is too record the whole band on two tracks or even one track and use it as a pilote.
When you get this right, rythm, feeling etc.... start overdubbing each track separately by recording the drums first then the bass and so on.
Try to record the tracks as powerfull and dynamicly as possible.
When the track recordings are done and you're about too mix it's time to use DSP's, compressing, reverbing and shaping the whole pack.
For software DSP I.E waves from steinberg, this is quite pro.
It's not the ultimate thruth but a good take off to make a pro recording.
One more thing, when you got things right leave mastering to a pro.They can make the difference in selling 10.000 or 100.000 copy's.
I hope this can get you on the right track.