I just started trying to read through Lectures on the Hyperreals: An Introduction to Nonstandard Analysis, by Robert Goldblatt. I expect to be asking a bunch of questions, including verification of some of my answers to exercises in the book. This is entirely a self-study adventure. How much of this background should I include in the questions themselves? Is there a convenient tag I can use for this?
Yes, you should include in each question what the background is. A question should always be as self-contained as possible. You can't assume that everyone knows what you have been studying.
That said, you don't have to include all the work you have done leading up to your question. You just want to make sure that the question doesn't assume familiarity with your other questions. If it does, you should link to the relevant questions.
Including source at the end of the question would be nice, both for attribution of material and for future readers. It can be separated from the rest of the question by a horizontal line, entered as
--- in the editor. You can copy-paste the author/title and add the relevant problem number.
There is no proper reference syntax in the editor. If desired, smaller font can be achieved with
A special tag is not needed. Tag names are limited to 25 characters, which is not enough to map book author/titles to tag names in a readable way. Also, tags should describe the content of the question, not its source1.
Some users even put the book in the title of the question, which I don't like: it sticks out too much, and takes up room that could be better used for describing the question.
(1) I dislike meta tags such as "homework", "self-study", etc.; but I may be in minority on this.