How do I format a map for maptools/vtt?
I will soon be putting my first map-pack up up for sale, and I want to include a version formatted for maptools/vtt programs. I could really use a veteran's advice as to how to format a map for maptools. I understand I should leave off anything that is likely to be moved/picked up by players (and include these as separate PNGs). I also understand I should have the base map saved at 100ppi (or sometimes 50?).
Should I just include all the elements separately (easy), or should I include a .cmpgn file with everything laid out in it, including setting up vision blocking? (if so, I could use a link to a vision blocking tutorial). I am currently doing above-ground buildings. Should I include a roof tile to place over everything?
I am sure I have more questions I haven't even thought of yet, but I'd welcome help/links regarding these things to start.