The Summer of Haskell is organised by the Haskell.org Committee. You can reach us by sending an email to
committee [AT] haskell.org. Alternatively, you can contact
nvazou [AT] cs.umd.edu and
m [AT] jaspervdj.be directly.
There is also a relatively active IRC channel called
#haskell-gsoc on freenode where you can ask for help.