Hitler was the quintessential 'douche bag', however, any person responsible for the deaths of some 50 million people is definately worth further and continued study. Learning about the man does not equate with honoring and respect. In most people I suspect the more they learn, the more exponentially the opposite effect increases. Those who consider him an unworthy subject of study are simply shortchanging themselves and history. I think one should never be afraid to ask the questions simply because the answers might scare them.
Anyway, buying a book about Hitler in the book store is usually rather entertaining as one dodges the stares and gasps of everyone in the immediate vicinity who automatically consider you some kind of ne-Nazi.
-EB