When you have two apple products?

This is kind of hard for me to explain…

When you have two apple products, say an iPod touch and then you get an iPad..can they both be on the same account?

I know whenever I get a new iPod I have to delete the old one from the account and it only lets you switch computers so many times.

If I get an iPad and already have an itouch will I be able to hook the ipa up to my computer for the iTunes Store and to put music on it?

Do I have to make a whole new account and seperate computer for the iPad?

Or does all the music and apps from the itouch go onto the iPad as well?

Thanks!
>>> When you have two apple products?