|The guild portal is activated by speaking to the gnome in the Guild Hall. You will need to purchase a focus stone from him and then hand it back in order to focus the portal on a specific location. Once the portal is focused, step on the crystal platform to bring up a yes/no dialog box. Clicking yes should teleport you away. (See this quest entry for portal details and destinations.)
Mana/Health regen pool: Walking into the back right room in the Guild Hall will cause you to regenerate health, mana, and endurance at twice your normal rate. You should see a text message when you enter the area of the pool as well as a particle effect on your character.
Buff timers are paused while in the Guild Hall. Various tradeskill tools are located in the Guild Hall for easy access by guild members.