Make sure your portfolio is at it's best. Make sure the gallery you're hitting on actually shows photography. Make sure you're talking to the decision maker, not some flunky.
My first show was 15 pictures, and stretched my resources to get them printed, matted, and framed so they looked their best. I compromised and used pre-cut mats to save time, and am glad I did.
This is a large topic. The biggest concern is the money. Frames, matting, and printing can be expensive. You may also want to put together a book to sell as coffee table. I would start researching frames early and try to find a deal for volume. You may find it cheaper to not use glass, and there is all sorts of glass from regular old glass to conservation glass. In fact many galleries will not accept glass, only plexi. It is not difficult to cut plexi yourself. You may find it cheaper to not use anything to cover the pic, and instead have them coated. For matting you may want to consider buying a cutter, but it is time consuming. Otherwise try to find a place that will custom cut or buy canned sizes in volume. Acid free mats and backing are a must for most galleries. Most galleries will only take wire to hang, but some want Saw tooth. Most galleries will look at web sites, but since you are looking for a first show, they may want to see the real thing. They will not want to see the whole show, but a sample of what they expect. Not only printed but framed and ready to go. I would have a CD ready to leave, the web site in top notch shape, and a portfolio ready. You have started some research, but you need to have some idea of the type of art the gallery shows. They may say they do not limit the type of art they show, but some curators tend to toward a similar type of art. Galleries are going to take a cut of what is sold. The amount varies. This is just a few things off the top of my head. Good luck. Shows are very rewarding they are also hard work, and expensive.
