I'm afraid your Alesis Multimix 8 USB mixer doesn't support this level of multtracking. It's a basic USB 1.1 device and it only provides a single stereo track to your computer, i.e. two tracks.
The most you could do would be to separate the drums into, say, bass and "rest of them", panning the bass hard right and overheads/snare/etc. hard left then recording that way.
To put each mic into its own track, you'll need to upgrade your interface.
This could be true, im kinda new to all this but the interface im using is a digidesign pro tools interface with a blue baby bottle mic. after reading your advice, i went and tried to record just a simple audio track and i still got no imput. I even tried to record with the same set up using Audacity and got the same result as in Audition (stuttering line at the 10sec mark with nothing being picked up). I just noticed that the light that says USB on my interface is not on, but my computer reconizes it as being plugged in and says its working properly. I think the interface is mono so I switched the tracks to mono and still got nothing.
Well, you have lots of options.
If you like the Alesis Multimix, its big brother the Multimix 16 USB-2 will feed up to 16 tracks into your computer. (Make sure you include that last "2" when searching--the original Multimix 16 was a simple stereo device like your existing one.)
Or, if you aren't wed to the idea of an actual mixer, there are tons of multichannel interfaces out there. I've been hearing of lots of people getting great deals on the Tascam US 1800--I believe that model is being replaced by a newer one so you can get them very cheap.
Failing either of those, just add up the number of simutaneous mics you want to use and go looking at a good shop or web site--brands I know to be good are M Audio, Focusrite, EMU, RME, MOTU and probably others I'm forgetting. They all do a range of interfaces including ones with multiple mic inputs.
Thanks a ton, Bob, I really dig the Alesis for the easy interface for a greenhorn like myself. Having read some reviews of the 16 - 2.0, I'm definitely going to stay with them. Hope this helps any further rookie like me with DIY multitrack recording. Would the USB 8 - 2.0 work in the same case? I assuming so because of the "2.0"
As for you Ryan, it may be a phantom power issue on your mixer. Having used the Alesis 8 on my windows PC (before I switched to MAC), I had to switch phantom power on in order to receive signal. There should be (literally) a switch near your power button if it has it.