It really doesn't take much at all. The cheapest route would be start with some cheap mics like the Oktava mc012's. They are about $50 each from Guitar Center. Next, you'll need a cheap mixer like the Eurorack MX 802A, which has 4 preamps, good for recording a drum kit. That should run you about $80. Now you will need some software. There is all kinds of software out there that you can use. You will have to do the reseach yourself on this. Just dont blow a bunch of money, there are plenty of cheap softwares that will do the trick. I use Vegas 4.0. Its more of a entire multimedia suite for audio and video editing. I like it because it is very easy to use and doesn't have a bunch of confusing bell and whistles. Kazaa was running a special on this one last time I checked
so your recording line will be ...
Oktava mc012 mics > Eurorack MX 802A mixer > PC
Not the best rig in the world, but it works great for me. It was cheap and I have been able to get some great home studio recordings. Its all up to you to research and learn how to mic your instruments and do all the mixing tricks to make it sound "professional". Have fun!
Here is a great place to learn all about home recording ...
http://homerecording.com/bbsBe careful, they will tell you buy thousands of dollars worth of equipment you dont need, just like these guys around her
, but if you read between the lines, you will learn all kinds of great recording tips.