Ok I'm new to the cake decorating world and have never baked anything other than like a box cake in 8 or 9 inch pans. My question is this....if you have a cake recipe and are using several different sized pans for stacked cakes, how in the world do you know how much batter to make? I found a recipe online and it says to use two 9 inch pans for this recipe. I'm not sure if I'm even on the right track but does anyone know how many cups of batter that is? I've never measured batter out in cups and is there some kind of rule of thumb or something that an 8 inch pan holds x cups of batter and 6 inch pans hold x cups of batter and so on and so forth??

Wilton has a chart that describes the pan size and how much batter.
No sure if I'll be able to type in the link because they sometimes don't allow it here, but I'll try. Otherwise go to Wilton.com and it's under Party Cake Baking and Cutting Guide.
www.wilton.com/cakes/making-cakes/baking-party-cake-2-inch-pans.cfm

If you check out the Wilton website under "Cakes" there's a section that lists baking instructions...and in that section you will find a handy chart that tells you how many cups of batter for the pans, how many cups of icing for a two-layer, how many servings, what temp to bake, etc. Wilton really gets a bum rap sometimes, I know there are products of theirs I don't like either, but they have a lot of useful information.

here is a guide for you:
http://www.wilton.com/cakes/making-cakes/baking-wedding-cake-2-inch-pans.cfm

Also, you could start pouring water into your pan, cup by cup, counting the cups as you go, until you get to the level you like to fill your cake tins to, 2/3 full or whatever you like. Then you'll know exactly how much batter your tin needs.

I have started writing on my recipes how much batter they make for future reference.

Thanks for the tips and links! Gah...this is such an awesome site! I could spend all day here reading and learning