Monger has a mailing list. Feel free to join it and ask any questions you may have.
Feel free to stop by #clojurewerkz on irc.freenode.net. There is a Web IRC client
if you need one.
To subscribe for announcements of releases, important changes and so on, please follow @ClojureWerkz on Twitter.
Monger is part of the group of libraries known as ClojureWerkz, together with Welle, Quartzite, Neocons, Langohr, Elastisch and several others.
If you find a bug, poor default, missing feature or find any part of the API inconvenient, please file an issue on Github. If possible, try to explain what behavior you expected and why. Bonus points for contributing failing test cases.
Monger uses Leiningen 2. Make sure you have it installed and then run tests against supported Clojure versions using
lein2 all test
Then create a branch and make your changes on it. Once you are done with your changes and all tests pass, submit a pull request on Github.