The official fan club, Adam Lambert Fans, can be found here: http://www.adamlambertfans.com
You must pay a fee to join. I believe the minimum fee is $9.99.
Any other entity, website, or contact person on Twitter, email, etc. claiming to be representing Adam's official fan club and collecting payments other than directly at the above website is BOGUS, NOT LEGITIMATE! Any questions you may have concerning any aspect of the fan club, including presale codes, VIP* tickets, Meet and Greet* opportunities, should only be addressed to the fan club moderators, DearBecky and addictedtoadam here on AO in the Adam Lambert Fan Club subforum. Please check to see if your question has already been posted in an existing thread there before posting a new topic. Please do not post questions concerning these subjects anywhere else on the forum. You can find the fan club subforum listed on the main forums page directly under Tour Talk. The direct link is:
http://forum.adamofficial.com/forum/30-adam-lambert-fan-club/ Fan club moderators, please correct me on anything I've posted that you find to be unclear or incorrect, through a PM. Thanks. *Meet and Greet and VIP opportunities may or may not be offered.