Since Brussels is heavy into business and politics, there is a wealth of hotels that cater to the business traveler. The bad news is that most of these establishments are going to cost more than most people want to spend. The good news is that, like most business areas, these hotels are empty on the weekends, which can lead to great deals if you plan your trip correctly. Some hotels include the price of breakfast into the room rate, so be sure to confirm this as a few of them will overcharge for bread and coffee.
Hotel Web Guide
This site offers an overview of the lodging available in Brussels.
This site offers their own list of recommended hotels.
A great place to find reviews from travelers just like you.
Free to join, this site offers good rates on hotels, some of which can’t be booked through conventional travel websites (Orbitz, Expedia, etc.). It’s good to check a hotel’s availability on this site and then check traveler reviews on Trip Advisor before booking.