When I log in, I check my subscribed threads. I have set it so that every thread where I post will be subscribed and whenever there's a new post it'll show up in User CP.
Then, if there's any posts, I'll check
Anime United board
GM board
bncy's board
spirit' board
Old Schooler's Crack Lounge
Hall of Shame
After those I'll quickly check the newest posts on every board from the main page. I might even check Off-Topic and Suggestions for interesting threads.
then I'll go do something else :p