I would like information on what dishes to add with the sea urchin.
Hmmm... This is a tough question! I'd suggest searching "sea urchin" or "uni" (its sushi name) in the restaurant reviews of major papers like the NY Times. It's a very popular ingredient in a lot of high-end restaurants and, by reading the reviews and discussion of individual dishes, you'll get a better idea of a dish's overall impression (and potential side dishes) than diving right into looking at recipes.
meaghan's advice is excellent. Uni is an acquired taste; i for one, really dislike it (it is actually the only sushi item I feel that way about.) But i'm guessing you have had and enjoyed it? It is certainly cherished by many . It is very soft/gooey to some, with a distinct taste of the sea. It is expensive as well. You want to make sure that you serve it in a very simple preparation that is going to highlight the uni and not another element of the dish. (think cucumbers, rice, pasta with soy butter maybe-some chefs puree it into a pasta sauce
It is absolutely crucial that sea urchin roe is extremely fresh when used in cooking or served raw, but I've heard of risotto using sea urchin roe which sounds fantastic.
Sea urchin roe is very soft, almost pudding-like, so it is good to use in a creamy-ish recipe, or for a contrast use on something crusty like bruschetta, with a nice olive oil.
Unless you are Down Under, sea urchins may be out of season. they are called ricci in Italian and are popular in Sicily--I've also seen them in Puglia. You might google 'ricci' and see what you come up with. this might help, too: http://www.bestofsicily.com/mag/art397.htm
Unless you have a live one. Don't try. Sea urchins go bad very quickly. Sushi places are often judged by their Uni quality. Even a day from kill to plate can be too much.