The document provides instructions for attending a mapathon event to contribute to OpenStreetMap. It recommends setting up an OSM account and bookmarking the tasking manager website in advance. Upon arrival, participants should connect their laptops to wifi and download any needed mapping software before the event starts. The tasking manager is then explained as a way to find and work on mapping projects, with color-coded statuses to identify tasks that are complete, in progress, or need fixing.