A slightly more philosophical piece of advice...
If you are just starting, I think the most important thing is to take note of what you are doing during setup, pay attention to how it sounds while tracking and mixing (obviously), and afterwards try to figure out why it came out that way. Don't stress too much about the details that you don't have the experience to make informed decisions about, those things will come naturally with time. Focus on what you can control at this point, like making the players comfortable and happy, getting the best sound from the instruments and amps, making sure everyone can hear each other, etc etc. And I've also learned that if you appear confident, the band will like the way it sounds. Good luck!
-Mike