Be sure that all founders and employees sign a non-disclosure, invention-assignment, and non-compete agreement prior to doing any work. Once more, see your lawyer.
Getting this done UP FRONT is EXTREMELY important. If you don't get invention-assignment agreements, there's a danger that your company doesn't own what's being designed, and that can lead to very difficult problems (see your lawyer!).
And if a non-compete agreement isn't signed early enough (way before a person starts to work) I'm told that in Oregon it is not enforceable.
Both employee and contractor contracts are something you'll want to be serious about right at the beginning! It's worth the lawyer's fees.