I second everyone's advice about visiting every sorority participating in informal rush. During formal rush, you have to visit every house; during informal rush, you don't, but it's still a good idea to take a look at everyone. After that, if you have two or three favorites, it's fine to focus on them.
Use the rest of your freshman year to your advantage. Get to know some sorority women - this way, they'll know who you are before you ever walk into a rush party, and when you do go to parties there will be some familiar faces.
Good luck - and keep us posted - we love rush stories
