http://supertuxkart.net/GSoC_overview for how to get started. Our list of ideas is here: http://supertuxkart.net/GSoC_topics_2014.
For those who don't know what GSoC is, information about it is here. Note that students should have read the FAQ as most of their general questions will be answered there.
Good luck everyone, have fun and we hope to have some nice posts to show in time. :)