Brno's bread and butter are regular trade fairs held at the exhibition grounds outside the center. Try to avoid arriving during a major fair (usually in May and Sept), when hotels raise rates 50% or more. The organizer carries a fair schedule on its website (www.bvv.cz).
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.