Engine rollers (which rolls, which don't)
 

So like all my cars, I wanna work on my own. It's a personal touch and makes me feel in time with my car. I just bought my first Audi about a month ago, used, and have had some issues that are self fixable. But my lastest issue is that last night I was driving, saw a bit of smoke.. I was close to home so I went straight there. While I was driving, the steering because SUPER tough to turn, and my battery light and check engine light came on. I discovered via this forum that it was the serpentine belt (big one in the front) that had possibly slipped. I checked this morning in the light and by gosh yes it was. So I read more and found out that it could be faulty rollers or a seized roller. I tried spinning them all an they all spun just fine, except the biggest one in the middle. I don't know a lot about motors but I want to learn. My question is which ones should be turning and which, if any, shouldn't?? I'd like to handle this issue alone but I'm not against taking it to professionals after I make an attempt.. Any input is perfect!! Thank you!! Btw, it's an Audi a4 Quattro (2002)

All the rollers turn by hand, except the lower big pulley which is the engine. That obviously drives the accessories via the belt. If everything turns fine and not noisy when spun, install a good quality belt from Gates or Conti-Tech.

Thanks!! Everything seems to be in order so I'm going to go ahead and try a new belt and hopefully it doesn't shred another one!!