The QGIS project is looking for people who are willing to invest some time to contribute to the brochure. If you want to help create and/or translate the brochure, please join the qgis-community-team mailing list http://lists.osgeo.org/pipermail/qgis-community-team/ or contact the QGIS Press Material Team Lead http://www.qgis.org/en/site/getinvolved/governance/organisation/governance.html.
The QGIS brochure can be used for any kind of QGIS promotion to give interested people an overview about the capabilities of QGIS.
The PDFs are available from http://download.osgeo.org/qgis/doc/brochure/
The source is available from https://github.com/qgis/QGIS-Promotion/tree/master/brochure
The brochure is designed using the open source publishing application Scribus http://www.scribus.net. Scribus will open the .sla source files from Github.