Mice have progressed a lot since the early days of the PS2 interface and the ball in the bottom that used to pick up more dirt than your vacuum cleaner! You’ll find it hard now to find a mouse that needs a PS2 socket as they are nearly all now USB and optical, so no more roller ball! I have used mice with extra buttons and my son has a large gaming RAT with loads of extra controls but my personal favourite at the moment though is a small, two buttons and a scroll wheel, cordless made by Logitech. Sometimes simpler just seems better.
A while ago a friend showed me the Photoshop software and I was transfixed by it and had to go and get it. It was THE best photo editing software but I just got the feeling while using a mouse that having a graphics tablet would make some of the tasks a lot easier. I wasn’t mistaken I went out and bought a Wacom graphics tablet. It makes doing things on screen, when you feel you should have a pencil in your hand, much more natural especially as its pressure sensitive as well so that can be set for making things darker of thickening the line. It’s not something you will use all the while but once you’ve used it for graphical editing or drawing you will miss it immensely if you have to perform one of those tasks and you’re without one.