This is based on my experience at hackathons and conferences and watching people try to use geo indexing for the first time.

A google search for "mongodb geo indexing" and a few other terms most frequently brings users to this page:
http://docs.mongodb.org/manual/applications/geospatial-indexes/

From there they move forward to:
http://docs.mongodb.org/manual/core/2dsphere/

The issue here is that they can't get a lot of the information they're interested in as fast as they should be able to because they're looking at the reference page and not the tutorial page. When possible it may beneficial to SEO the tutorial pages above the reference pages or find a better way of linking the two together.

I propose either adding a link to or embedding some of the information included at: http://docs.mongodb.org/manual/tutorial/query-a-2dsphere-index/ to the page that most people land on.