A buddy of mine just bought this boat: http://www.tahoesportboats.com/boat/index.cfm?fuseaction=boat.model&nav=20&boat=1715 he was asking me what size prop he should put on it to get the full potential out of the boat. Can anyone help me out please? Thank You

I would imagine something in the 23" pitch range if he plans to pull skis, maybe even lower like 19" Pitch.

what is the difference between the pitches? Higher pitch=more power? or the other way around? Thanks

The lower pitch props are better for hole shot and pulling power, while the higher pitch props are usually better for top end performance. On a boat like the one in the picture, usually opt for a lower pitch prop because they are very heavy and most folks are towing skis or tubes with them, or carrying a boatload of people (additional weight). Bass boats, on the other hand seldom have more than two people and have a design built for speed. With jackplates and lift strakes under the hull, bassboats usually opt for the higher pitch props for speed and topend performance.

does the motor size make a difference? I know that it has a 220hp on it. Thanks Bob, you are giving me good info.

I have a Powertech prop in stock that will work very nicely on that boat.

Striperhunter04, Power to weight ratio is definitely a factor. The more horses you have back there the higher the pitch you can get away with. I would still try and find out what your buddy's intentions are with the boat? If it is for the pure sake of pulling folks around I would still suggest the lower pitched props. Mike sells the props he told you about and I know absolutely nothing about that brand. Mike is reputable and if he says they are good props, then far be it for me to question him.
Regardless of the brand always start with the lower pitched prop and work your way up. Most dealers will let you try several props when you buy the boat, you just have to bring the prop back each time and tell them what you want to try. They are obviously not going to let you take a bunch of them at one time. Although there used to be a couple of prop shops, not too terribly long ago that would meet a bunch of boaters at one of the local ramps (like Dove Rd. on GV) and let you try different props on your boat, in hopes that you would buy the one you liked the best!

You need to learn to trim and run the boat with the prop that is recommended and installed by the manufacturer. Then is it doesn't meet your needs check with a professional shop. Running some high tech prop can damage the drive train...don't ask how I learned this.

Not very helpful but will help to envision the difference in props is: For every revolution a 19 pitch prop will move the boat forward 19" assuming no slip. A 23p likewise 23".
As to prop size, tell him to ask Bass Pro Shops. They will know more about it than anyone.