There is a fantastic online community, The Asexual Visibility and Education Network or AVEN, which we encourage people to check out particularly for information about what asexuality is.
Aces NYC focuses on building a face to face connections and community. We meet at least twice a month. The first weekend of each month we try to have a fun activity, such as going to the Brooklyn Botanical Gardens, a picnic in Central Park, museums, etc. Then we get together to talk about ace related topics and hang out the third weekend of each month. In addition we help with all Ace related events we can, such as The Ace Un-Conference: AVEN CAKE and work to reach out to other groups of aces neighboring cities.