Disclaimer: Last time I mentored is years ago.Back then the ASF applied as a whole to be accepted as organisation for GSoC. I remember Uli Stärk explaining once to me some of the paperwork required from the "OSS project side". Upon acceptance, Google granted several dozen slots for students, those were then distributed across projects. The exact process should be on the com dev page here:
http://community.apache.org/gsoc.html Isabel
