In this discussion you will find links to Zone maps.
I will also include important links and information for different regions. 
From the National Gardening Association Map

From the National Arboretum Map

For our UK and European Gardeners


From the UKGarden Web Map

From BackyardGardener Map  Australia
                                       Map New Zealand
                                       Map China
                                       Map South America
                                        Map Shows East of Moscow