It depends on my mood. And the time I have. And whether I feel I have anything useful to say.
I'm often pressed for time, so I tend to scan the 'headlines' of the Main and General Chit Chat and see what tweaks my interest. I do read other bits of the board, but those are the main ones if rushed. I tend to also limit myself to the first 3 pages of threads, unless I have more time. I know that if I go into Pictures that is a rabbit-hole, so I do that if I know I can give it a reasonable amount of time.