As a beginner, stick with the bigger distributors for a while.
Tower Hobbies www.towerhobbies.com is the retail arm for all of the brands listed at www.bestrc.com
Horizon Hobby www.horizonhobby.com is the US distributor for another huge portion of the industry. eflite is distributed by Horizon.
Hobby People www.hobbypeople.net handles all brands imported and distributed by www.globalhobby.com
There is one site www.advantagehobby.com that sells items from all 3 big distributors