Having a hard time finding specifics, could someone link me to some materials concerning licensing issues of Ubuntu, and link's at large?

I'm considering starting a business installing custom/embedded computer systems, and the open source nature of various Linux distros makes them the most attractive candidates for final installation. I just want to make sure it would be legal to do so.

Would I be able to charge for installation of the OS? If not, could I provide the customer the physical means for installation (CD, USB)?