There are several websites you can check.
For ASA in the Sacramento area it's
http://asatournaments.com/For NSA there is the main website at
http://nsacal.com/ - it says 2011 tournament dates will be released on Friday, 12/17/10.
For USSSA - it's
www.usssa.com. Just saw one posted for February.
Then there are always the organization websites, like Grapettes and RR Gold, that list their tournaments (Grapettes are usually ASA and RR Gold are IFA).
I have found that tournaments aren't really posted until after the 1st of the year, and are getting updated probably until the end of January. Take the ASA website I listed above...it only lists tournaments that Gary Ybarra is putting on in the Sacramento/Lincoln/Roseville area. Usually Keith DeGeorge puts on a few, plus other tournament directors, so I feel safe in saying that is not "set-in-stone" list.
Hope that helped! You can always google what you are looking for...and once you reach out to the tournament directors, they add you to their distribution email list, so you get updated when the list changes.
Good luck to you!