What kind of web medium you use to find other nudists depends on your purpose. There are general social networks, personal ad sites and other websites that may have a way to search for those interested in nudism and naturism.
Here are a few great places around the web to find other nudists:
NetNude.net A long time host of personal profiles, pictures and general nudist information.
ClothesFree Forums The World's Largest Naturist Community
Nudist-Resorts.org World's Most Complete Nudist Discussion Forum and Bulletin Board
Personals or More Nudist Dating-Oriented Sites:
In addition to nudist and naturist websites, another way to go is to try to search more general-interest websites for words like “nudist”, “naturist”, “clothing optional”. Some systems may not allow these search words or profiles may not be searchable.
While it's great to meet new nudists/naturists online, another great way is to find a local nudist resort and meet folks in-person! Nudist resort events and busy weekends can turn out larger crowds where you’re more likely to find the type of person you're looking for. As far as nude beaches go, it's harder, at least for a male, to meet others. People may be more on-guard, due to gawkers and other potential trouble-makers, and there is usually no automatic medium or activity that makes it easy to meet others.
One last thought – if you're having trouble finding other nudists in your area, consider meeting non-nudists and introducing them to nudism! If you want to save yourself some time and trouble, this could be your best bet to begin with.