I make cakes as a hobby, but they get quite a bit of attention, and now I've been asked to make one for a coworker's son's 7th birthday. She wants a cake that will feed 15-20 people. I think I know how I am going to decorate it, but I'm not sure how big of a cake I should make. I was thinking of making two 9x13's and layering them, but will that be enough cake? I think if I did two half sheets and layered them it's gonna be waaaaay too much cake.

check out some of these links it will help you.
http://www.createacakeshop.com/businesscakedec6.htm
http://www.wilton.com/cake/cakeprep/baking/times/index.cfm

Thanks! Those sites are helpful. Who knows...maybe this will turn into a profitable little side biz for me.

That's how we all started! Helen