I want to make a 3 colour scheme lit pc case. Haven't got a clue about electronics. Any help welcome.?

I want to make a pc case that has three different lighting options ie to either show, red, blue or green inside the case. I have ordered some cheap pre-wired led's but want to know what I need to do as I haven't got a clue about electronics and how to wire things up. I have two cases one windowed one I intend to. In an ideal world it would be great to have them alternate colour through some type of timer and also have manual option of switching between the 3 colours. Real WOW would also be if I could also incorporate sound activated as well. I have tried looking on some instructables but they seem to miss vital steps ie what wire goes where and from what source to what. Many THX