Thanks... and a few questions

Hey all.

To start out, I just want to say thanks to all the great people on this site. All of the feedback that has been given to others has helped me more that you guys know. Thanks!  

A few questions...

I was reading the intro article, and it mentioned that an older bike with a 600cc engine would be acceptable for a newbie to learn on. Can I have some clarification on that statement? How old of a bike are we talking about here? I was looking on Suzuki and I saw the 2005 GSX-R600 had a 599cc engine (but also that it was a four-cylinder). So would this be a good bike?

Also, could someone give me a link (or a quick run down) on how engines are classified? Least powerful to most powerful? If that's asking to much then just ignore it. If not, thanks a lot!  

- Nick