There is no stable release of the Wikibase Query functionality yet, and even in the development branch, the feature set is far short of what I guess you want to use. One thing that is not entirely clear to me is if you want to query data from Wikidata.org, or from your own Wikibase Repository instance. In any case, have you considered Semantic MediaWiki for your use case? http://semantic-mediawiki.org/
> Any help would be appreciated, it looks like Wikibase documentation for reusers is not terribly great yet.
Indeed. We have essentially no user documentation on the features of the software that is not specific to Wikidata.org. Then again, we also do not have stable releases or usable release notes for our main applications (Wikibase Repository and Wikibase Client) suitable for third party users. I hope we can improve these things in the near future, though one has to hold into account that third party users are not amongst the first priorities of the main developer of the Wikibase software, the Wikidata team.