If you’re renting a server from a host:
If you need help with your rented dedicated server, your first port of call should be your host. You’re paying for the service, so you should be using their support lines first.
This doesn’t apply for gamemode or addon queries.
If you’re looking for a host to rent from:
Have a look at this: http://wiki.garrysmod.com/?title=Index_of_Gmod_Server_Hosts
Whatever you do, don’t post any threads asking “What Gmod server hosts are there?”! You’ll be banned for not reading this sticky.