itunes and sync issue

[JuiceBoxHead]

Ok, I need some help. My husband and I just got our iphones and I am trying my hardest to figure this thing out. I am trying to get ringtones from itunes so I hook up my phone to the computer and go into the itunes icon on my desktop and for some reason my phone is trying to sync up with my husbands. I don't want this to happen cause he has a bunch of apps and stuff that I don't want on my phone. When I go into itunes I have my email and password in there but I am assuming it is still thinking that its my husbands phone, I have no idea. So what I am trying to figure out is how can I plug my phone into my computer to use itunes from there without having to sync to my husbands phone. Why is it doing this? If anyone understands what I am trying to say, please help, I'm clueless. Haha. Thanks.