I'm new with fondant... my first experience with it was making my daughter's birthday cake. It turned out... well i rolled it out and i had no problem placing it onto the cake but it was hard to cut and chew!!! What did i do wrong and what am i suppose to do actually to make it edible??? 
You didn't say what brand of fondant you used.
If you used Wilton, well unfortunately that's what happens.
My Dad and one of his friends had a chance to taste Wilton fondant when only an hour on the cake. They both said it sucked. I'm not actually allowed to repeat the words they had for it on the site. 
If that's what you used you didn't do anything wrong.
All fondant dries hard, so it can be hard to cut. Next time I recommend Satin Ice, Fondarific, Fondx and my personal favorite in flavor Choco Pan. I think I've listed them in respect of their prices. Lowest to you must sell an internal organ to afford it.
There are HUGE differences in fondant out there. You need to find one that tastes good and performs good. It's so important.
99.9% of all my wedding cakes are fondant. They taste, they buy
Jen
Quote by @%username% on %date%
%body%