The DTMs here that have their own CDs/kits usually have something along the lines of:
(a) their name, CD/kit name, copyright, etc.
(b) font, filter, etc. usage
(c) terms of use: submission to mags/online for publication, for websites, for commercial use
(d) prohibitions: cannot be altered and resold as your own, cannot be shared with others/through e-group, cannot be used for profane, immoral, or illegal purposes
(e) contact info for creator and website
I think that's most of it.

You could also include directions, if you wanted, for how to change color, how to use in a certain kind of program, etc.