For the creme de la creme of WWII wargaming guides to painting (although aimed specifically at 15mm and out of my chosen main scale of 20mm, but there is tons of cross-over) must be the two Flames of War Battlefront Guides. Not cheap but a worthwhile investment. (Note: No sign as of yet of a issue number three though and the Germans as per usual get prime time in the spotlight!)
The main reason for my excitement being the Vallejo painting guide cribs and tips, plus the ultra level of detail they go down too. Hence I am all primed to get that German "red track" look (comes from the factory red primer seeping through the tracks) on my German vehicles, now I know which Vallejo paints to use ;)
Yes, I seem to be doing far more reading than doing as of late as house renovation takes priority. What a twisted world I live in.