I am not aware of a Preview Weekend at Arkansas. More than likely Panhellenic will have some sort of presentation/table set up when you attend summer orientation. The Arkansas Panhellenic recruitment page has some great information (
http://uagreeks.uark.edu/panhellenicrecruitment.php). If you scroll down to the bottom you will find the magazine type publication from last years formal recruitment. It talks about what to wear, the schedule ect...it's definitely worth a look. Make sure you get 2 recs for each sorority....the page also has some great links under the sub heading of "Letters of Recommendation", one of which will take you to the Area Panhellenics. These groups are a great resource for acquiring recs.