How do I keep an NZXT S340 cool?

[Walkeri]

I recently purchased an NZXT S340 case. I also purchased an MSI R9 390 graphics card, but I heard that the card runs really hot, so I was wondering how I can keep it cool. I know the case has one fan on the top and one on the back, but it has two spots for fans on the front of the case. Will the two fans it comes with be good enough, or should I buy a couple fans for the front as well? My room has bad air conditioning and gets pretty hot so I'm a little worried about that. Also, should I keep it on top of my desk, or on the carpet beside it? I'm new to this, so any advice with cooling would be great, thanks.

 

[nostall]

I always like to err on the side of caution, if you will: Fans are relatively inexpensive compared to other components, so I would invest in at least one good quality fan for the front; of course two is better.
I would avoid the carpet.
Carpeting, depending on time, may block the air flow into your PSU; and at the very least it will place the PC closer to the dust and dirt of everyday living. If you can live with it on your desk, put it there.
If you must put it on the floor/carpet - invest in a 1-2 inch thick piece of wood, just a little wider and longer then your case, and put that under your PC: this will assure that the PSU airflow is not blocked and may help keep some of the dust and dirt out.