1. Go vertical, as in don't just set up a table and lay out your items. Use shelves, boxes, stands, etc. to really show off your wares and make the most of your small space.
2. Less is more. Use your space wisely. If stuff is piled up everywhere, it is hard for the eye to land somewhere and decide on something to buy. Keep your booth stocked, but not overflowing
3. Set up ahead of time. Put together your entire booth before the actual event to make sure everything will work as you would like it to.
4. Plan to have at least twice your inventory to fill your space. As I said before, less is more, but empty shelves are not good. Plan to hide the extra merchandise under the table or behind displays.
5. Consider transportation. Although a huge book shelf may be just the thing, don't forget that you will have to lug it to and from the event. That being said, perhaps you can create the same affect in a collapsible form.
6. Make it shopable. I know that I am a lot less likely to buy something if I am worried about knocking the whole display over by picking the item up. In this same thread, things that are eye level are usually more likely to be purchased.