I jsut got started and want to try and make my first tiered cake. The thing is, I dont know how long I should cook a 6", 10", 12" or 14" cake. Does anyone know? Thanks in advance fro any help you can offer!

Part of it will depend on what type of cake you are making since they don't all bake the same. With the larger pans, I would suggest using a flower nail or heating core in the center for even baking...that way the outside doesn't burn before the center ever gets done. I always know my cakes are done by look and smell.

This is great reference:
http://www.wilton.com/cakes/making-cakes/baking-party-cake-2-inch-pans.cfm

It has the amount of batter per pan, baking times and a serving chart. Just a note, everyone's oven is different so you may not get the exact timing. Most people will tell you to bake it until it's done.

I bake my cakes at 325 degrees so they take a bit longer to cook but I don't even open the oven until 35 minutes for a 6 inch cake. Just take notes as you make things about approximate baking times and keep that handy.

I use the "smell" technique! When I can smell the cake in the oven, it is done.... I have never used a timer!!

Thank you so much for all of your help! I greatly appreciate it!!!

Also don't forget the toothpic test. Insert a toothpick in the middle of the cake and if it comes out clean it's done, if it still has cake batter on it, then the cake is not done.

I still use a timer, but only for an approximate time, or I'm inclined to get involved with someone else and forget about the cake. But the signs it's done:
1) it starts to smell great... get up and go check it
2) The sides of the cake are JUST starting to pull away from the tin
3) if you jiggle the tin from side to side, the cake doesn't wobble
4) if you gently press down on the middle of the cake, it will spring back up. If it's not done, the indentation takes longer to rise up again
5) when all of the above are done, poke a kebab stick down the middle of the cake and inspect it when it comes out. If it's still damp, give it five more minutes. If it comes out with crumbs on it which are not wet, it's done, but you'll need to leave it sitting in it's tin for 30 minutes or so, the heat of the tin will finish the final bit of cooking. If it comes out totally clean, get it out of the oven, and out of the tin once 10 minutes or so has passed to let it settle a bit.

I made a cake last night which the recipe said would take between 25-10 minutes to cook, took about an hour fifteen minutes... seriously! I think the reason is that the recipe called for three bananas (6oz). I peeled my first banana, dropped it in the bowl on top of the scale, and only needed a tiny bit of the second banana before it hit 6oz. A bit confusing, so I just dumped all three in, figuring it would only make it moister if that was the wrong thing to do. If you add more liquid like that (banana became liquid after I whizzed it up) then the cake will take longer to cook. Same thing happens when I've added condensed milk to cakes before, they take longer to cook. My point in all of this is not to trust what the recipe says, it's just an approximate!