"...how does one get this guidance, besides Mr Bob posting these every
once in a while..."
It's really no different from, say, joining a conversation at a party.
You listen in for a while to get a sense of the conversation before
entering it yourself. In a newsgroup this is called 'lurking'.
Lurking is a tradition as old as newsgroups themselves. It means to
follow a few days or weeks worth of posts to get a sense of what topics
are being and have been discussed, the tenor of the conversation and, in
general, what are the customs and conventions of the group. Then you
make your first post.
If more people would spend the time to do this there would be 1) much
fewer posts, since most are asking the same questions over and over, and
2) fewer problems within the newsgroup, since users would understand how
the group works and how to use it to best advantage.
Newsgroups are of limited usefulness when it comes to answering
questions. Some people have difficulty forming a coherent question (and
they probably have the same problem outside a newsgroup too.) Many
people lack the technical vocabulary to describe their problem
accurately - you can hardly blame them. And there's only so much that
can be achieved by writing back and forth. I see many people here who
would be much better off in showing their computer to a professional.
Finally, it seems that many posters don't understand the dynamics of a
newsgroup, which are defined by the NNTP protocol. They expect to
receive a complete and accurate answer in real time. Or they expect us
to remember what they or someone else wrote in some earlier post, or
what the post 'three lines above' is. There isn't much you can do for
people like that.
A web search is usually a better way to find the information needed to
solve a problem. Many people don't know how to find information on the
web, or they're too lazy to make the effort, so they post here instead.
And they expect their fellow users who volunteer their time to
understand their question and provide a detailed explanation almost
immediately. For free.