i say a good 4 pack of roundovers (and decent brand that uses carbide) is helpful. Also a small 4-5 pack of variety bits. Then get a set of rebetting bits (probably pays to buy quality here since replacing a set isn't cheap and these will be used lots. finally, a good flush cutting bit. I'd try to stick with 1/2 inch shanks when possible. Everything else can probably be added as needed. hope this helps. hopefully i didn't forget anything (assuming cabinet bits will come later).
PS - some find undersized plywood bits helpful too.
PS - some find undersized plywood bits helpful too.