Humanist Organizations
Some good organizations are:
The American Humanist Association
American Atheists
The Humanist Society of America
Council for Secular Humanism
In addition there are a number of local and regional groups
that you should be able to find on any search engine. They
can have a number of activities you may find useful and
can be a source of support when needed.
The Greater Worcester (MA) Humanists have the following
page as a good example:
http://www.meetup.com/worcesterhumanists/
Check it out!!
Scroll down to see the various activities they have