Hey Babs,
I will tell you what very little I know. We went to the Atlanta gift show in July and it was great for us. Expensive, but a good experience.
The major gift shows, from what I understand are: Atlanta, Dallas, Los Angeles and New York. You should be able to find them simply by googling the city and gift show. There may be a Chicago one, I'm not sure.
I'm also interested in the outdoor retail show. I think it's part of our market. We're still working on developing our line; I think we'll be ready for the January gift show here in Atlanta, but I don't plan on travelling to any shows yet -- plus the Atlanta show is supposed to be one of the biggest, if not the biggest. Thankfully, it's right in our back yard.
For us, we went to the Atlanta show with SIX t-shirt designs.

We went just to get a feel, an education and hopefully sell some shirts. We sold enough to cover the expenses associated with the show. The value of what we learned was worth more than what we paid. It was great for us. We researched a LOT before going and were very prepared thanks to some super advice. I'm NOT an expert, but I will be glad to share with you anything from our experience that might be helpful...
-Kristie