Only do minimal this year to see what fruit you get, for a start..cut out dead wood.

And make sure it is definitely dead. We don't know where you are located but in Spring leafless doesn't necessarily = dead.

I highly recommend you check out davewilson.com. You will get a good education about growing fruit from beginning to end. Everything from soil requirements, pruning, fertilizing, etc. (including multi-grafted trees and how to care for them and taming overgrown trees). I agree that you should not do much this year in the way of pruning -- remove dead wood only. You need to know what you have. I would also suggest that you take lots of notes and photos throughout the year. groworganic.com and starkbros.com are other great sites. Their websites have great tutorials, videos, etc. Have Fun!

Read a lot first, do some research. Read more before you cut. Reading is cheap. Cutting is permanent. Best of luck!