Lets say I have eight different MovieClips. A user can randomly select the
ones he want. The first four selected will go one page 1, the second group
will go to page 2. I have no idea how to do this. I was thinking about useing
arrays or duplicateMovie. Can anybody help?

what do you mean by "...four selected will go one [sic] page 1..." and "...will go to page 2."?

The user will select them by click on a check box next to picture of the MC.
The first 4 selected will appear on one MC on the stage and the next 4 will
appear on another MC on the stage. Both MCs represent a page a user can see by
clicking on that pages button.