When gluing canopy and clear parts *after dipping/drying in future for the clarity) use elmer's white glue and a toothpick to glue the clear parts on. The glue will dry clear, but not gunk it on thick. If you use otehr glues, the clear parts will craze and get futz'd up.
I'd start with something easier than a b17 for your first attempt, because even if it's 1/72nd scale it's a decent size and brush painting for large areas is... meh... consider getting a few cans of testor's spray (they do make them in military colors.) You can get away with brush painting 1/72 fighters... depending. 1/48 and up only spray (can or airbrush) can do it justice. You will still do a lot of brush painting of cockpits, interiors, engines, fiddly bits...
There are a ton of modeling sites out there... I like these:
http://www.modelingmadness.com/ http://www.hyperscale.com/ http://www.scalemodelindex.com/http://www.aircraftresourcecenter.com/ not to mention all the actual warbird sites to use as reference/research.
have fun.
