It will depend upon the country or region in which you want to do gliding. If USA, I know nothing that could help.
If UK, I could help a little – we have several ATPLs who have joined my gliding club and are now solo glider pilots. At present there is no mandatory/state-issued glider pilot licence in the UK, but that is going to change under EASA, during a transition period from April this year to April 2015. I understand that it will not affect things until 2013 or 2014.
If elsewhere in “Europe” (i.e., where EASA rules apply), it will depend upon the local state of affairs, but many or most have a formal gliding licence already. You would need local expertise to advise about whichever country you are interested in.
Chris N