The first time I took my pictures "out there", I went for City-run gallery spaces (as opposed to private Art galleries). I applied to three such spaces and to my joyful surprise, all three accepted my exhibition proposal. My show contained 40 odd framed prints as all galleries offered me plenty of wall space. The shows went very well. I even got a great newspaper review and a morning-TV interview along with several sales not to mention an exhibition-assistance grant from the government (which paid for all my expenses). All in all, a terrrific first experience.
If there are such spaces where you live, you might want to try this approach to get your feet wet. It is not as daunting an experience as you're going to get in a private gallery and it is likely to be seen by far more people as those galleries are usually more "accessible".
IMO, 20 prints is a bit thin in number and you might want to have a few more handy just in case you find a lot of wall space available. Show them just like Jorge suggested. Investigate what grants or assistance are available out your way, too. You might be pleasantly surprised in the possibilites.
Don't take critique personnaly but do take it as a learning tool. What you feel is a strong print may be quite insignificant to others.
In any case, let us know how things turn out for you, Alex and best of luck.