I've thought of the attic fan idea. The only problem is I might need 2-3 of them because of how my roof is divided. That is still an option for me. As far as the shingle color goes. I'm pretty far away from having my roof redone. And yes, of course my shingles are black. They werent doing alot of "green construction" back when my house was built.
dont wait untill you are ready to have your roof replaced. i believe you can just paint the shingles. i see contractors driving around all the time with something on the sides of their trucks mentioning roof painting.
you could just roll some white paint on with a roller or spray it on with a sprayer. either way having your roof white will help keep your house cooler and reduce energy consumption.
if you are not COMPLETELY convinced, by what i say, to paint your roof white. atleast research it online.
as far as needing more then one fan. are the different areas of your attic completely isolated from each other?
a dont put off installing a fan untill you do all 3. if you just install one, for now. the energy savings will help you save some extra cash to get the others done sooner. assuming cost is a factor.