Is there a list of luxury resources?
Solution 1:
I highly recommend the "Luxury Resource Display" mod. It's one of the higher-ranked mods at the moment, for good reason - it makes you permanently just a mouse-hover away from seeing a detailed list of how many luxury resources you currently have of each kind, including how many are traded.
Just search for it in the in-game mod hub, it's easily found, but it seems to also be downloadable from here (I recommend the in-game method, though).
Solution 2:
The latest patch added a "Resources and Happiness" tab to the Economic Overview screen. I can't get a screenshot at the moment, but I think it shows similar information to the mod above.
Now that I'm home and can check it out, it shows you all of the above and a whole lot more. Individual city contributions to unhappiness and happiness, all the resources that are available and what you're doing with them, etc.