What to outsource?

I’m still having doubts about which projects to outsource. Should I outsource the small, easy-to manage ones or should I outsource the really BIG ones that make up around half my company’s annual revenue? I sometimes get the feeling that quality will suffer if I outsource since I wont be there to constantly oversee the work being done. My co-workers jokingly say that i’m too much of a control freak for my own good…

I’d really appreciate feedback from anyone who’s been through this situation before.