Okay, this is probably asked before, but i couldn't find it... I saw Dann put music into his map, and so i wondered; is it possible to add new sounds for an unit? If this is so; how would i do that? (which format, how to get it that format and how to get it ingame?) Thanks in advance!

Aye, it be possible. Check out the "everything you need" thread, it has a section about sounds.