I know at my school on the first night after all the freshmen have moved in, they all have this picnic type thing in our gym (like all 4000 of them, its insane). I remember when I went to it, a lot of the clubs and some sororities had tables set up so they freshmen had to pass by. I stopped by the DG table and talked to some of the sisters about rush. They also gave me a sheet of paper with anchors all over it and it listed the week of rush, the DG website, and a few other things. They also had some tshirts and pictures on their table.
I think some cute things to have on your table or booth would be tshirts, pictures, paddles, and maybe a recent composite. I also liked the info sheet DG gave me because I checked the website a bunch of times before rush.