hello :)
what kind of set up are you working with? and what are you trying to record?
initially if it helps this is a kind of quick setup-
1. mixer (mic or otherwise) in some cases these will have a tape out or master out for recording. or if you prefer you could get adapters like a 1/4" Stereo Jack to 1/8" and directly plug your instrument into your comp mic input that way.
2.computer software for processing. i.e. asio is an awesome freeware program for input processing it's also usable with any music/mastering program such as fruity loops or soundforge and many others.
http://asio4all.software.informer.com/
or you could simply use the basic microphone input line on your comp you will get less depth in sound but either way it will work pretty much just the same. additionally in the freeware world from what i know audacity isn't all that bad for recording just kind of limited in controls and mastering.
http://audacity.sourceforge.net/
but if you want something that will layer and/or separate tracks with better depth and processing quality you will need to buy something like sony acid software especially for stuff like compiling tracks and general mastering with more tools.
anyway i hope that helped somewhat :D
there are a lot of different ways to go about this especially for different kinds of music
so if you need any other steps i'll be around