My school always hold a "Meet The Greeks" event in the student union about a week before formal recruitment starts in which 5 reps from each sorority assemble tables filled with pictures, balloons, flowers, albums, paddles, flyers etc. It's always sooo crowded with PNMs and a pretty interesting, fun night. (The fraternities are in a separate room, but many of the guys wander over to the sorority room to check it all out
Then a couple days later, there is an outdoor event held outside the Union called "Fall Bash." (formerly "watermelon picnic") It's basically the same as Meet The Greeks, but outdoors, more casual (the sisters wear letters as opposed to business attire), and refreshments are served. This is usually the less intimidating way to meet some sisters and preview the sororities.