How hard is it to do yourself? I am mainlly talking about valves seals, and valve seats. I do not know anything about this so please help me out. I was thinking about just sending them off but now I want to learn to do it myself.

Thanks in advance

You can change the seals yourself. If you have a valve & seat grinder, you could do the seats yourself; otherwise, you'll have to send them out for those.

How much would a shop charge to redo my heads?

call shops in your area for pricing, and it'll depend on what parts you need. basic clean and regrind cost around 150 here and takes 2-3 weeks.