Bigger Tires, lift, or both?

I have an 07 king cab that is all stock right now. I wanted to put some bigger tires on it but not sure I have the clearance in the front to go any bigger. So a few questions for the experts on here:

1. How do I know how big of tires I can put on without a lift? How much clearance do I need in the front to be able to turn properly?
2. If i do go with a lift, what kind is best and what price range am I looking at if I pay someone else to do it?
3. Is putting a lift kit on yourself do-able for someone with only a normal set of tools or do you need crazy tools and excessive auto know-how and experience?

Thanks for your opinions.