It's not clear to me how we're supposed to map the use of Mantis to our 
workflow.

This should be documented, perhaps in such a way that clicking the "Docs" link 
in Mantis actually explains something, instead of displaying an empty page.

What do the various choices mean for severity, status, and resolution?

How do changes to these choices relate to specific actions by members of our 
community?

For instance:

When someone posts a fix to Mantis, what is the status and resolution supposed 
to be set to?

How does one choose between "minor" and "major" severity?

When someone tests a proposed fix and wants to recommend that it gets applied 
to the update stream (i.e. harvests it), how should the bug fields change? 
Should this become "resolved"?

When a fix goes to the update stream, how should the bug fields change? Should 
this be "resolved" -> "closed"?

-- 
Ned Konz
http://bike-nomad.com/squeak/