I went to Brussels a few times for work about 10-12 years ago but I don't have much more practical advice to add.

I didn't have very much opportunity for sightseeing but I did get a chance to wander around the Grand Platz and the surrounding narrow, cobbled streets and check out the great little shops. I remember lots of lace shops, and chocolatiers (yuumm). And my coworkers had an uncanny ability to find great old pubs, but that's not very difficult to do there. Do check out the beers if you're so inclined, they are not at all like the beer we have in the states. I always marvelled at the fact that every beer was served in it's very own, distinctive glass.

If you like mussels, that's a speciality of many of the restaurants. Molues, I think they were called. Served with pomme frites. Yuuum.

Hope you have a great time.

- Jo.