Here's an easy way to do a seating chart. Print each guest's name on a master list, then cut out each name into a strip. Then cut out ten or twelve circles, each representing a table, writing on each a number. Now you can start placing the guest names at each circle, or table. Move them around the tables as you see fit, until you have a good placement for each guest. Once that's done, type out your seating chart.
Hope this helps!
Below is a link from this site that was designed to help with seating:
I think this is a fantastic tool to help with a difficult task. We recommend this usefull tool to all our bries who have small weddings at our unique venue in New Jersey, the Carriagehouse.
The Woman's Club of Englewood
Click on each tool to see a sample.