Pre paint prep?

[wakeboarddrumma]

Hi,
We'll be getting my truck painted sometime this summer. I was wondering what we should do before taking it in. We hace already sanded and primed the cab, and I am going to do the bed as well, because those were the two places with the most rust. So will they take it apart to paint it or what?? Also, is there anything else we can do to save ourselves some money?

We just brushed on the primer on the cab, because it'll get sanded down anyway when they paint i assume.

Thanks
Chad