I am looking for a site or guide that will tell me where to look for mirco printing on US stamps, they can be really hard to find if you don't know where to look, a web site or some place to send am email to. Thanks
That is the whole idea of the micro printing, to make it difficult to find. To my knowledge there are no books about it, but some of the specialized stamp clubs list the position of the micro printing every time a new stamp is issued. For instance, I collect plate number coils, and all micro printing on these is reported in the journal "Coil Line".