Are you setting up the recording gear yourselves or will you be in a studio with an engineer? If you have a decent engineer he should be able to do a basic mix as you are recording, you just need to arrive with two or three examples from bands with the sound you want to achieve so he knows what you are looking for. If it's just yourselves and you havent a clue about mastering, then just try recording the rythm tracks as tights as you can with whatever sound you like the best one to the far left and one to the far right. Then put the bass guitar in the middle - this really fills things out. Lead should be a little off centre and to the opposite site of any other drop ins' with vocals in the middle. It's amazing what a little sound placement can do. I'm going to a studio myself in about 6 weeks for three days and will have an engineer throughout. I'm a one man band so I will be doing all rythm tracks at home through a mesa boogie rectifier recording preamp direct to pc through an M-Audio Delta 1010. This saves a lot of time and the preamp provides real studio sound (not like digital modeller) as it is anologue. Solos will be done in the studio because the most time needs to be spent getting the tone right in between take 100 of some crazy run (head wrecking).
If you can, try recording a full rhythm track onto a laptop and then out of the pa for your jam sessions. It helps to get ultra tight, but also, if you can get the quality good enough in the comfort of your own home you will then be able to spend more time getting the drums and vocals right and get a bit of mixing thrown in at the end.