Society is, for all its marked improvement over the last 50 or so years, still prejudiced and narrow-minded, and nudism does take some of this flak, so it isn't as simple as walking down the street and bumping into the local nudist clique.
Websites such as NudistDatingSites.net are designed to help nudists find others in their area, be it for a relationship or a friendship, and then there is the American Association for Nude Recreation (AANR), which offers lists of Places to Go across America – nudist clubs, nude beaches, nudist / naturist resorts – and information of upcoming events at those locations.
Of course, this isn't particularly helpful if you aren't from America, but it's still possible to use the internet – just do a search for “nudist community/club/etc. in [YOUR AREA]” and you should come up with something.
The AANR makes it easy to search for events in your area, and attending these events is an easy way to get into the community. Some parks and the like require you to have been a member of the AANR for at least a year before you can head on over without clothes on – a necessary precaution to combat those who think nudism a sexually-driven lifestyle.
If you are planning on going to a club or a resort, be sure to phone ahead and find out about their rules and etiquette. Most places will restrict photography to certain areas or prohibit it entirely to protect the privacy of the patrons, and will have any number of other policies. Treat planning your event-attendance or holiday at a nudist resort as you would any other holiday – find out everything you can in advance, make your bookings.
Otherwise, just visit the community forums and listen to what people have to say. There you will find out about upcoming events and popular locations, and be able to start communicating with others.