In here, you will find some interesting links that you probably already know, but for those non-initiated, this cant be a great ressources spot..|
STA league ()
Stronger Than All. STA is a league with alot of different games like TFC. Most of the clans on it offer a great challenge.
OGL league ()
This is the most common league for any clan. Range from newbies clans to expert clans, you'll probably find someone with the same skills as you to fight against.