Find a new relay team:) Sorry, I couldnt help myself.
I'm not really all that educated on placement for relays, but I'll tell you what I think anyways from my experience.
Umm, Id give the girls the turns and the guys the straight aways, but which ones I dont know. If one of the girls is better out of the blocks then give her the 1st leg. Now for the first straight away, it depends on preference. I think the 1st straightaway is the longest, so it would make sense to give it to you and let the other guy anchor. However, if you feel more comfortable running the anchor then give the other guy the 1st straight away and you take the last leg. As for the third leg, give it to the girl who is slower out of the blocks.
Thats just what I would do.