I followed the directions on this website and it turned out great. It was easy to make and there are tons of FAQ's and pics that show you step by step how to make the fondant and how to apply it to the cake. The most important tip I found on the site was to use the exact same size of cake board as the cake. You put a can or something stable under the cake board.Then you can roll out the fondant about 2 inches larger than what you need, then the wrinkles in the fondant will be in the excess fondant that gets cut off. It makes a perfect, wrinkle free cake, which seems to be the hardest part.
I made a 3 tier anniversary cake that turned out so great because of this website.
If the web address doesn't work for you, type Fondant 101 marshmallow fondant into a search engine and it will come up (usually the first entry)
The icing is kind of a playdough type of texture and kind of sweet but it was MUCH better than store bought. It stays pliable. You can draw on it with icing markers and I didn't find that it showed fingerprints at all. It's not that expensive to make so whip up a batch a do a trial run!
Good luck on your project!!