The BGA has a nice poster on their facebook page, good review of the
basics... may be a good idea to share this with your clubmates

link for facebook users:

https://www.facebook.com/BritishGlid...type=1&theater

I took the liberty to make a copy available to not facebook types here

http://silentflight.ca/thermalling.jpg

Cheers,
Luke Szczepaniak