[Electriclight]

You will lneed an audio interface. Use the Soundcard Wizard on this site to help give you some suggestions.

You will need to decide how many simultaneous inputs you will require, if you prefer a PCI card (that would mean going inside your computer to install) USB, or FIREWIRE, whether or not you want MIDI capabilities, adn if you need phantom power (Probably, see below.)

Nearly all audio interfaces come bundled with good recording software, so I would hold off on purchasing any until you are sure you need it.

You will want some monitors to mix by. (Studio monitors are special speakers with a flat response.)

Since these are acoustic instruments, you will require some microphones, probably at least two of which are condensor microphones (these require phantom power, usually supplied by the audio interface).

A few cables and you are good to go. A minimal budget would probably be $500 and the sky is the limit. Realistically a nice setup would run around $1000. But you will get all kinds of opinions on this. What I think is a luxury others may think is essential.