Trying to create a DVD menu as a beginner project in animation. I've modeled a ring that I want to spin on its z axis fast and then slowly come to a stop.

Adjusting using ANY tweener curve doesn't make any change to the object. I'm wondering if that's because I used the preset spin modifier (fixed number of cycles per second). If so, any ideas on how I can make the ring spin 360 degrees?

I tried just creating keyframes, but the rotation limit is 180 degrees. Like I said, I'm a beginner at this, so any help would be greatly appreciated.