That's a good question, Wayne.
Take photos of your work and keep them (always), as well as slides. Send the slides to the gallery for their review.
Then I would draw up a simple contract between you and the Gallery, however if this gallery doesn't already have a contract it's reason to be suspicious. Basically, the contract states that your work will be displayed at such and such gallery until such and such time when it will be shipped back to you.

Also, is this the first time the Gallery has ever displayed work? If they have displayed work before and given the work back to the Artist, chances are that they would do the same for you. Find out as much as you can about the gallery or venue before you ship your work, such as how long they have been established, the names of the curators, etc.

There are some challenges, or more like challenging gallery situations, good to do some research on the place and people too... I usualy try and hunt down web info or printed material on the past exhibition artists, and call them up, "hi, would love to know of your experiences with..... gallery" ask a few if you can....
and yes...
take pictures, good ones, making digital presentations is becoming more invited, keep the original work as safe as possible, pack it really good, there are tons of print opportunities out there too.
I am excited for you Wayne
your art is very appealing packed with potential and it would be great to hear of your progress
cheers
leah