In the fall you can find local craft shows in the local newspapers, but the best place to start is to know somebody who does craft shows. Failing this, go to some of the local craft shows and ask around. Usually you can find the person in charge who can add you to the mailing list. Ask the individual crafters, they will be more than glad to help. You can check the internet, get on mailing lists for craft sites, try local searches.
Don't be bashful, ask how much the admission fee is, the "rent". You may want to try one or two of the "free" craft shows, but they just don't compare with the ones that charge. The "big" 2 or 3 day shows usually cost quite a bit more than the small ones you will find in churches and schools, and you will probably have to raise your prices and sell much more just to pay the "rent". On the plus side, the big shows get much more advertising and a lot more customers.
I really think the best place to start is with the small craft shows in schools, the rent will usually run from $30 to $50, and the turnout will be fair. Once you figure out who to talk to you will have to get on their lists, then fill an application. Sometimes they ask for photos, take some good photos of your best items, they will be returned to you later, usually at the craft shows.
Take that first step, if you get into craft shows, you will love it.