The most recent version of this document can always be found at http://kipper.york.ac.uk/mouse.html
There is a Japanese translation at http://jf.gee.kyoto-u.ac.jp/JF/JF-ftp/euc/3-Button-Mouse.euc; and a French one at http://www.freenix.fr/linux/HOWTO/mini/3-Button-Mouse.html. Other translations may be available - check your local LDP mirrors.
Most X applications are written with the assumption that the user will be working with a 3 button mouse. Serial mice are commonly used on computers and are cheap to buy. Many of these mice have 3 buttons and claim to use the Microsoft protocol, which in theory means they are ideal for the X windows setup. (The record for the cheapest working 3 button mouse currently stands at $1.14!)
Most dual-protocol mice will work in two modes:
As distributions become easier to set up, some of the problems ought to go away. For instance, RedHat have a mouseconfig program to set things up for you. However, some versions of RH5.0 had a bug in mouseconfig, so make sure you check for patches.