Some people may not exactly know what they're doing when it comes to steam, or how to use all its features, so here's a brief mini-guide on how to access chat for those who are unaware, or a prone to forgetfulness:
1)Right-click steam icon in wherever you keep your icons
2)Click "Friends"
3)In the friends console that has now been brought up, beneath the search bar will be two tabs, "Friends", and "Groups". Click "Groups".
4)Click the drop-down arrow next to "The Hall of Odin Veterans".
5)Click "Join Chatroom", and you will enter the chat
This shold help anybody who doesn't understand how to enter, or often forgets.