Contributing to postgres driver

Hi all,
as a Postgres enthousiast and an old Java lover I'd like to contribute to the
Java driver. i've seen a list of things to be done but I'd like to know
how to help ? What is the usual process ? I could take one or 2 tasks and
try to complete them but if someone fix them too it's a waste of time..

Thanks for any pointer or any suggestion
Cheers
jerome