I think it would be helpful if the Python documentation included certain high-level information about multi-threading in Python.

At minimum, I think it would help for the documentation to provide a definition that can be linked to of what it means when some part of the Python documentation says something is "thread-safe".  In particular, such a definition could clarify that this is different from being atomic.  This might best be addressed by an entry in the glossary for the term "thread-safe".
  
Other documentation possibilities include stating what guarantees one should or should not expect regarding thread-safety, both within and across implementations, and providing centralized guidance on how to approach multi-threaded programming in Python.  A HOWTO is one possibility for addressing these other possibilities.

This issue stems from the discussion in issue 15329, which is more specific.

This sounds like a good idea. Either a HOWTO or a FAQ would sound appropriate.

If no one gets to it first, I'll write-up a draft when I get a chance.

Given the scope of the issue, a concurrent programming howto that lists some of the available options and the caveats associated with each of them seems worthwhile.

This seems somewhat related to the "We need to document Python's concurrency and memory model" that came out at the language summit this year.