Hey,
congrats on getting the ps3. But, if you didn't buy it yet, you should check out the x360. I find it's controller better and more comfortable. Also you should check the games you want to play. Xbox and Ps3 have different exclusives. One thing that I think ps3 is better is that it has free internet connection, whereas with xbox, you have to pay monthly for xbox live.
But still, I prefer x360 more. If possible, go out and check both consoles before buying.