I would say Definately upgrade your Sound Card to an actually Milti-Input Recording sound Card....You can get something like the M-audio 2496 or the EMU-0404 for about $100 which is Probably cheaper than your audigy was and you will notice the Sound Quality is Much better....
Then I would suggest some Mic Pre-amps or if you are on a budget pick up a Cheap Small 8Ch Mixer which you can Probably get for under $100 which you can connect to the Sound Card ....The Mixer will come in Handy especially for Micing and Recording Live Drums and you can use it"s Pre-amps to Run your Microphones and Run your Guitar and Bass through.....
So for about $200 you can get started with a Beginners recording set up(Minus Mics) that will get you started recording....
And there are a few Freeware Recording Programs(Audiacy,Reaper,Krystal) you can use till you have money for a More advanced program....
Cheers