Where would be the best place to start?
Just as there is a lot of different types of magic you can do for "street" or close up, there are a lot of different types of magic you can do for stage. You are going to have to look around and get a sense of what you want to do.
The first stop that I'd reccomend is checking out stage magic on any on-line magic store's website. Most of them have a link along the side for stage magic. Click on the link and go through what is available and see what jumps out at you. The is so much from Airborne to the Zombie Ball that can be used for stage.
If you like cards, you can use Jumbo Bicycle Cards for stage presentation. To learn how to handle jumbo cards, check out Dariel Fitzkee e-book Jumbo Card Manipulations on lybrary.com.
Also consider learning mentalism. It plays well on stage and doesn't require a lot of props.
Finally, if you are considering doing large stage illusions, check out Paul Osborne's website: osborneillusionsystems.com. Also, some of the stage illusions in Mark Wilson's Complete Course are pretty good.