You can download Mt.Bromo Trail map here. Good luck!
Tip: You can take the road that leads all the way to View Point 1 (right hand side of the map). About 1 to 1.5 Km from Cemara Indah Inn, you will notice a trail that leads you all the way down to the open space. If you take this route, it should be about 3 to 4 Kms trek to Mount Bromo. You can also skip the entry fee for the National Park (as of writing, they charge about IDR 20,000 per head for foreign Nationals).