My suggestions:
Train on the surface that you will be running on. Treadmills are good and all, but your body needs to get used to running on asphalt.
Hydration (water, not beer, ha) should be a daily focus. Not just before/after your runs, but every day you need to be drinking lots of water.
No new foods/drinks on race day. The time when you are training is when you figure out what works best for your body. If you haven't tried eating or drinking something and then running, DON'T try it on race day. Your body might not react well to it.
Stretching is soooooOOOOOoooOOOOoo important after any kind of workout. Running in particular can be hard on your body, so you need to take care of it. Not stretching is a great way to send yourself straight towards an injury (trust me, I know). Also, invest in a foam roller and use that to work out tightness in your muscles. Listen to what your body is telling you (if you are tired, sore, etc. then take a day off -- it will not hurt you!), and abide by that.