What exactly is the difference between 'performance frames' and 'performance prestrung' racquets (as I've seen in Sports Chalet)?

Performance prestrung racquets are better suited for beginners, because they are already strung. This means that the string they use is most likely the best for the racquet. Performance racquets that are unstrung are usually for seasoned tennis players who have a specific string they want to use and know what tension they want to use.

They mean exactly what they say. The frames are just frames meaning there's no strings. The prestrungs ones are already strung. For beginers, you'd probably want a prestrung one.

And basically the person above me said the same thing. -.-

Thanks both for the information.

Btw, another question - what brands do you suggest (I'm actually choosing between Prince, Head, perhaps Wilson but I'm not sure what kind to get.)

Get a Head, if you're any good. If not stick with a Prince, maybe something in the triple threat series.

triple threats are pretty good, ncodes are awesome as well but of course if ur a beginner it doesnt matter. Skill level determines matches more than rackets do.I wont MVP on both jv and var and my teamates know its not the racket that makes the player. =)

It's definitely not about the racquet, but having one that works for you helps a lot. You should start playing with a cheap one and determine whether you want more power or control and things like that. Then go do some research.