Hi - we've been thinking of creating a knowledgebase for a while that would contain this kind of reference.
However, in the meantime - as well as the manuals, there are useful queries on the blog (hasn't been updated in a while, but will be resumed shortly) and also this Q&A site.
To find useful queries that you can adapt on the Q&A site, you can go to the Search bar in the top right of the screen. Try typing in "SQL", "MySQL" or "query".