A bit of research on the likes of BeerMapping, RateBeer etc and then sort myself out. Lots of good book[/url:1i9u7t8m]s on the subject too.
I'd heard[/url:1i9u7t8m] Beer Mania had stopped doing tours. Maybe he's started again. If you're interested in visiting lots of breweries some sort of organised tour might be a good idea -- most of the cool breweries are quite inaccessible. Stupid monks...
Personally I could spend quite a lot of time just between the pubs and restaurants Brussels and Bruges, throwing in Ghent and Antwerp if time allows. Travelling between them all by train is really easy too.