If you're traveling by car, you can reach Split on motorway A1 Zagreb-Split or by state roads 1 and 8. When you get to Split, drive some 4 km to city port where you board on a ferry to Supetar.
When you land in Supetar, there's just a short drive to Bol (32km). When entering Bol, take a left turn, then in the third street on your right and there you are!
Split is connected with all major cities in Croatia by bus, and there are also direct lines to Bol. Regular lines exist between Supetar and Bol too.
You can reach Supetar or Sumartin with ferry, Split with direct catamaran or ferry lines from Italy and Bol with direct catamaran lines from Split.
Directly to Brač Airport (only 15km from Bol) or to Split Airport.