Getting into an exhibition is lots of work - and then when you get it, it's even more work!
Here are a few thoughts:
1 - Enter juried art shows for photography. If you want any kind of gallery to look at you, you need to have a resume that includes JURIED shows. And that way you get at least one image in the show. Check places like artdeadlines.com (I think that's the right URL) and Google the term "juried art show photography."
2 - Make some good prints and put them in a boxed portfolio. Galleries like boxed portfolios rather than books. It's a different market. Pick a reasonable size - matted to to 11x14 or 16x20. That gives you an image size of 8.5x11 or 10x15. I like to present 10x15 in 16x20 mats. If you don't own a mat cutter and archival tape, the mats are going to cost you. Remember to give yourself a 1/4 inch or so around the print as a gutter to hide the tape and still get the entire image. If you have a particular size that you think is "right" for your work, make ONE print at that size as an example and mat it out to the proper dimensions. I have a large portfolio carrier that I use for the large prints.
3 - Take a photography class at a local university and see if that leads to some "student" show opportunities.
4 - Join some local arts organizations and find out if there are not-for-profit spaces in your area that show photography. One of the issues in having an exhibition in a for-profit space (like a gallery) is that whether they like the work or not, it has to SELL to be worth having a show or you're just taking up their valuable wall space.
5 - Make a list of resturants and clubs that might have art for sale on the walls. They often rotate artists in and out, and sometimes have a reception or opening to kick off a show.
6 - Write an artist's statement for the show to use as a supporting document. Any art space will what to know what you're intent is with the work - just a pretty picture doesn't do it.
7 - Plan your show. Decide how many images you can provide. 5 - 15 is usually a good range. 5 gets you in a group show, 15 is enough to do a one-person show. Know how long it will take to get prints made, matted and framed. Know where you're going to make the prints and have the work matted and framed. I had a friend get jammed up on getting enough matching frames - he assumed that he'd just be able to walk in and get 22 16x20 black metal art frames. WRONG.
8 - Don't print the show and expect to take it around looking for a venue. Have a portfolio of prints that REPRESENT the work and let the space help you chose the images for print. Depending on the space and what they're offering, you might be printing something that mats to 16x20, or (my latest proposal) something that mats to 28x38.
That's a few thoughts. Lots of ways to go at it - but the thing you really need are some nicely matted prints in a portfolio box that helps show the work. The 8.5x11 matted in 11x14 works pretty good - and that way you can print an artist's statement on heavy grade paper and mat it with the rest.