If you view this link you can see the problem I'm experiencing with my users. 

The editor box is set at 550 pixels wide, but when they add an image that is too wide, the scroll bar appears in the editor and still allows for the wider area.

Can I limit them from scrolling?

I thought I could have images automatically resized when they inserted them in?  Can I and if yes how?

Please help asap!

Thanks!