Teaching toddlers about stranger danger & private parts through books?

I was thinking on getting some of the books out there such as " my private parts are private " or the stranger dvd from america's most wanted. Does anyone have any recommendations for these for a toddler who is going to bre 3 soon? I know a lot of parents say its uncomfortable and etc.. to read these to the kids, but if you think of what it cna prevent i guess im willing to go for it. i just dont know which books are worth investing in (or dvds, or ??)