Wow, seems like I've missed out on a bit these couple days. I've been kept crazily busy. ><"
Seriously folks, just ignore tenniscraze (I think it's a he?

). I thought I could have an intelligent conversation with him, but I tried to no avail. Ah, alas and alack.
Shoe: let me dig up my old message to you since I'm too lazy to retype.
Themes -- by far my most favorite event. Basically you come and see the house decorated in a theme, and the sisters put on a skit that really lets the personality of the house show.
House tours -- you tour the house! And there's also food everywhere to eat. Take my advice and DO nibble on something. I was too scared to and it really doesn't matter to the sisters if you do eat something. Well, unless you claim the whole platter of truffles or something (yep, truffles. There are truffles!)
The rounds are callbacks yes, you have to go to a maximum of seven for themes and five for house tours. So if you're invited back to more than that, you have to do some pruning. If you're invited back to less, you go to all of them. In no circumstance can you miss going back to a house (it sucks miserably when you're tired), otherwise you'll be cut from rush.
And to fill in on the two I missed, the first round is round robins. You visit ALL the houses for 25 minutes and speak to three to four different sisters while you're in there. This is the round when the notebook and pen will be most helpful, since your head will likely be whirling after three/four houses. Or you can do what I did, just let them all run together and see which ones I remembered most strongly. The sorority I eventually pledged gave me a pleasant surprise of 'Oh, I rather liked that house and the sisters' after my round in there. That was also partially cause I was still sleepy (first round of second day) and really tired from my second day.
Prefs are a very respectful round. Several sisters share a deeply personal part of themselves with you. I personally was very touched by the atmosphere of subtle friendship and support that I felt throughout this round.
With regards to what I wore, I wore the same thing for both days of round robins. Jeans with this stretchy Japanese print top and my favorite pair of black heeled shoes. The shoes were a bad idea, my feet were seriously hurting at the end of the day since they were three inches tall. Near the end I was like 'Oh I'm so happy to be here now where's that sofa...?"

(Because rushees get to sit on chairs in the houses while the sisters usually kneel in front of you. Yeap... kinda awkward.)
Themes and House tours the outfits kind of run together... I wore the same jeans and a long collared dark grey tunic. I wore the same shoes again inside the house, but slipped on half sneakers once I was out. It was kind of amusing actually, but the second round all the girls had learned to bring comfy shoes to wear whilst walking around from house to house, but would kick them off before lining up to go inside and putting heels on. It may be superficial but heels do give you some more confidence. And you'll need plenty of that. =)
As with the dresses, I can understand it. After a while it just becomes this huge awkward hassle to have to simultaneously greet the sister at the door, extend your hand to shake it, drop off your name card, take off your coat, and do other assorted things with your hands. Plus, each time you take that huge winter coat off you (well, I personally do) feel the urge to check my hair, tug my shirt, etc. I got fed up enough that I just ditched my coat for prefs.
So shoe, yes to jeans and nice top. I don't think any sororities will be doing fall rush since we're all at quota. Quota this upcoming semester is at 95 girls, and I know my sorority as well as a couple of others are at 95 or over. Fall rush is usually chalked on the ground, and I'm really hazy about fall rush details since first years weren't allowed to rush then. Sorry. :S But yeah, do spring rush. I take it you'll be an incoming second year?