This is the first time I will be making a three tier cake and using fondant. First question, can you eat fondant or do you peel it off the slice of cake before eating? (It is store bought) Second question, when placing the cakes on top of each other do I need anything in between?

Fondant is definitely edible. Many people don't know what it is and don't know what to do with it so a lot of people peel it off but you sure can eat it.

You need some sort of cake circle or cake plate in between your layers and also some sort of stacking system - there a many posts about different types. You need dowels (wooden or plastic) or something actually in your cake layers holding up the cake circle/cake plate for the layer above it. The cake itself will not hold that much weight.

There is an article in the articles section about stacking...this might help:

http://www.cakecentral.com/article49-Building-The-Cake-Combination-Pillar--Stacked-Construction.html

A quick note about the fondant, if it is Wilton's it is edible, but don't eat it, it tastes horrid.

Totally off topic...just had to say, lanibird, I too wish Jack was my doctor! LOL!!

My friend uses satin ice "fondant" instead of wiltons and it tasts soo good. I would only recommend wiltons for flowers and decorations like that. I would do each layer individually with the fondant.

I used Wilton's fondant ONCE. The taste alone was enough to turn me off of it for good! Ick!

However, marshmallow fondant is much cheaper, easy to work with, and TASTY. When you get a chance, try a batch. It's great! (And did I mention it's yummy?)

ditto on the stacking... separator plates of some sort and dowels or thick straws for supports are a MUST. (The first time I tried to stack without supports, I learned a very valuable lesson... And a messy one!)