Ok, to get your mouse working with all it`s features have a look here,
www.xfree86.org/current/mouse4.html
It will run through how to configure your mouse and gives you xf86config options, it even gives you configuration examples for several of the most popular mice (including multi button)
This involves editing your "xf86config-4" file, so make sure you gather as much info as you can and make sure that you are doing the right thing. although just changing the mouse section can`t really get you into too much trouble if you muck it up.
Also i believe that when you get your extra buttons working that it will work with konqueror for back and forward but not mozilla. I don`t know this from experience just from what other people have said. But give it a go and find out. I think all the info you need for what you want to do will be there.
Good luck Cheers
