You should visit Kiermusy flea market in the summer Sunday. It’s kind of a country picnic, Polish style. It's about 10km from Bialystok, the main city in the area. Bialowieza is worth seeing too. Trust me, you'll love it.
Quick Tips: It's better to be there in the summer. Polish winters are rather rough and cold. I would suggest staying at least one or two weeks in order to see the whole region.
Best Way To Get Around: The best solution is to have a car. If you plan to travel on a bus, you might need at least one day in each place. If you can stay longer than the recommended time, you can surely decide to travel by bikes.