Getting set up:

1. (Install and) launch Counter-Strike: Source once, then quit the game.
2. Subscribe to all workshop items in this collection.
3. (Install and) launch Garry's Mod. It should start downloading the workshop subscriptions.
4. Click the game controller icon on the bottom right, and make sure Counter-Strike Source is checked.
5. When it's time to play, join a friend's game, or follow the instructions at nickcagemat.ch to join the server.