I am planning to make a cake for my boyfriend for Valentine's Day this year, and would like to use fondant. I have never used it before and am not sure how much I should buy. It will be a two layer heart shaped cake. I'm not exactly sure about the size of the pan, it is a silicon heart pan that appears to be 9" by 10". I am wanting to cover the entire cake. Any help would be greatly appreciated!!! Thanks!!!

I would suggest using homemade marshmallow fondant. All you need is powdered sugar and a bag of marshmallows. Basically you must melt the marshmallows in the microwave with a little bit of water and then mix and knead the powdered sugar in. It can be a little messy but it's a lot cheaper than store-bought fondant and tastes better. Most people I know really don't like the tast of the store-bought stuff. You shouldn't need more than one recipe of the marshmallow, you'll probably have quite a bit left. Here's a link to an easy recipe and instructions:
http://whatscookingamerica.net/PegW/Fondant.htm

thanks!