Hi Lauren
It just so happens that I'll be a Junior at the University of Iowa in the fall and I am involved with the greek system there so I can most likely answer any questions you have or find them if I don't personally know them.
Iowa rush is the week before school starts - which is August 19-25 this year. You'll be able to move into your dorm and get settled the weekend of August 17/18... On monday or possibly sunday - i don't remember, there will be a Panhel/IFC sponsored luncheon for you and your parents to learn more about the greek system and get acquainted with your Rho Chi's and rho chi groups. The first round of parties will begin on tuesday morning and end Sunday with Bid day.
All incoming freshman will recieve a Greek Life booklet and I think theyre sending interactive CD-roms this year - which are very cool - In it is more Greek life info at Iowa and an application to sign up for rush. All you need to do to sign up is fill this sheet out and send it in with your check. More than likely it will be coming by the end of June - and if it doesn't call the Office of Student Life (319) 335-3059 and just ask them to send you one!
Unless your registration advisor is greek (which I know quite a few of them are) greek life isn't talked about at registration - but definitely ask around - and if you see any girls on campus wearing letters when youre in Iowa City for registration, stop them and ask about greek life - I know they'll be more than happy to tell you lots of wonderful things.
Check the rush forum for rush tips - but honestly, I know i'm looking for someone who is themselves and very genuine - someone who was involved and wants to stay involved, a person I think would make an amazing sister.
If you have any questions - feel free to PM me