Check back here often, as I will be adding lots of useful tips. My first two tips:
Reduce wrist strain & increase efficiency
Those of us who use our computers frequently are susceptible to wrist strain. The right hand is especially vulnerable as it does all the mousing. For less than $100 you can reduce wrist strain and improve your efficiency at the same time: buy a new keyboard. Now, not just any keyboard will do. If you trust my judgement then buy either the Microsoft Natural Keyboard Pro or the Microsoft Office Keyboard.
Each offers lots of extra buttons that you can set to open your e-mail, access a favourite web site, mute the volume on your CD player or Internet radio (very handy!) or many other shortcuts. The main differences:
Microsoft Natural Keyboard Pro is ergonomic, with the two halves of the keyboard split slightly and angled. This takes a few days to get used to, but it is much more comfortable on your hands and wrists. Once you use one you'll never want to return to a normal keyboard.
Microsoft Office Keyboard includes an area on the left called the Touch Pad, controls to reduce your mouse use and make it easier to edit and work in multiple applications: a scroll wheel; back & forward buttons; cut, copy and paste buttons; and an application switch to quickly toggle between open applications. This set of controls is very useful.
Now the hard question: which one do I prefer? Well, what I really want is a combined keyboard. I want the ergonomic shape of the Natural Keyboard, but with the great controls of the Office Keyboard. As Microsoft hasn't produced that yet, pick the one most appropriate to you. If you often switch back and forth between multiple open applications and do a lot of editing, you might want the Office Keyboard. If you tend to just type a lot, then get the Natural Keyboard Pro. Whatever you do, don't just stick with your current keyboard. Either of these keyboards will make your computer use far more comfortable.