Suggestion: search the old forum, there are lot of threads on the Wiimote.
Other suggestion: perhaps first take a look at the tutorials and examples, before jumping into more advanced stuff.

do you want to do "something like the wii" or connect the wiimote to processing
if you want to do that.
search for "darwiin" on the board

http://sourceforge.net/projects/darwiin-remote/

but like philho suggested... its not trivial, so maybe start with some more  basic projects first

http://processing.org/discourse/yabb2/YaBB.pl?board=os_libraries_tools;action=display;num=1186928645