Agonies of a Young Author

With blogging there has to be a certain amount of interaction between the two parties, but sometimes, of course, that can step over lines. What are the rules for blogs, a personal, instantaneous means of communication, but frequently used in the professional sense? It really is confusing, and my mind is drawing parallels to the situation when the phone or email became commonplace in society (I've been reading some old etiquette books written right after the invention of the portable telephone-- remember those old brief case phones? Well, not me personally, but I've seen movies...-- and the fax machine. It's really been a hoot to look at those books. Apparently, they used the fax machine like email, for fast communication, and wrote personal notes to one another's home machines, like invitations to parties, etc) It's like we don't know what the boundaries are, and are only finding out after that boundary has been crossed.