A Tutorial/Help System
A sign saying "Read rules at pluscraft.org" and "This way to start" doesn't help out a new player. Make something like Mineplex's tutorial system where you can be rewarded with something in the end.
Signs on the arch-ways are impossible to read, having a cinematic camera or a positioned camera with text appearing in the chat will help a lot when you first join.
Or to prevent griefers, a test with command blocks to teach them the rules.