Yeah, take at least two rest/recovery days prior to the ride 3 works best for me but everyone is different). If you are going to do hills, intervals, or a hard ride do them today and tomorrow so you have plenty of time to recover. Eat a relatively normal mean the night before like grahny said if you are not used to 'carb-loading' or have never done it before it can cause problems. Just eat something good the morning of with protein and carbs.
My best advice is this: don't eat something really spicy the night before-I made that mistake before previewing the course a couple weeks ago.
Also, I don't think that I stressed this as much as I meant to in my previous post-The engine is right-this can be a very dangerous course, so BE CAREFUL!!! Take it easy on the down hills, there will probably be a lot of riders not used to group rides on a lot of narrow roads with poor pavement and a lot of sharp blind turns. Let's keep it safe!
BTW I heard a rumor that Lance will be riding...