This page contains some links that make good bookmarks for SpamAssassin developers and contributors. Please feel free to add more. Note that a link to this wiki isn't really necessary though
How to use keyword bookmarks in Mozilla/Firefox: right-click on the link, select 'Bookmark This Link...', and add it to your bookmarks. Then open Bookmarks -> Manage Bookmarks..., find the new bookmark, right-click, Properties, and type the desired keyword string in the Keyword: text-box, hit OK, hit File -> Close. Once you've done this, you can then use the URL bar as a command line to search for strings; e.g. sb ALL_TRUSTED
will full-text search all open bugs for the string 'ALL_TRUSTED', and bug 3406
will open bug 3406.