The regions (oblasts) of Belarus provide no real guidance for a tourist. These divisions are of purely administrative nature, were created less than a century ago and have very little to do with historical, cultural or ethnographic matters.
Belovezhskaya Pushcha National Park (map) — on the border with Poland, this primeval forest is a UNESCO World Heritage site.
Travelling by train around the country will get you to a lot of desired destinations relatively cheap and fast. Timetables for all means of transport can be found on the site of the Belarusian railway.
Inter-city buses are cheap, relatively comfortable and relatively punctual but may be more expensive and less comfortable than trains. (infobus.by)