get yourself an audio interface and a good mic. the interface will allow you to connect your guitar and mic through your computer via USB or firewire. it will also include the software needed for recording and editing. you can get a small two input interface for around $100.
if you intend of recording live drums, you will probably want more inputs and mics to get the best sound off of the kit. you can also use a drum machine or something like that if you don't have a kit to record. you can get drum machine packages to work with on your computer. drumagog i believe is a good one, but i'm not for sure on that.
when it comes to mics i would spend a little more than you would like. i've heard the Rode NT1a on metal vocals and it's great. it sells for about $240. for guitar i would suggest getting an SM 57. you can record your guitar straight into your interface if you want to. perosnally i would record one directly in, and record an amp as well, then mix them together as one guitar track. it depends on you and what you have and want to do. for a cheaper vocal mic you can go with an SM 58, its another industry standard in studios and live events.
you can find package deals on guitarcenter.com sweetwater.com or musiciansfriend.com which can include an interface and mic, or mixers and monitors. you can usually find a good deal in there to get yourself started.
the cheapest way to get started would be a USB mic and downloading audacity. i don't know how well a USB mic will be on tracking a guitar amp. i've heard decent things about USB mics, but haven't used many. once you get to drums, using one USB mic will not capture a good drum sound. however if you want to use a drum machine it wont matter.
good luck