Along with
www.isra.org the Illinois State Rifle Association, I'd add
www.illinoiscarry.com it was very instrumental in getting carry legislation passed and when it started working with ISRA on the Illinois Gun Owners Lobby Day the attendance grew greatly, this year it was about 5000 people that went to the capital to Lobby for Concealed Carry legislation. Illinois Carry has worked for the past 10 years on getting carry legislation.
I'd encourage Illinois folks to join the Illinoiscarry.com forum to keep up to date on legislation good and bad that is being introduced in the legislature.