Check out the big names in chairs

The brand name manufacturers have informative and interactive sites.

I recommend: Start your window shopping at Herman Miller, Hon, Knoll and Steelcase. Once you know what you want, you can often find bargains at sites like eBay and Craigslist. You can also scan online liquidation sites like Liquidation.com for deals.

Consider lower-priced options

Office superstores sell serviceable and relatively inexpensive chairs. Just be careful not to get something too cheap – you may regret it later And avoid chairs designed for conference-room use: They're typically not designed for prolonged sitting.

I recommend: Moderately priced office chairs are available at Staples, Office Depot, Ikea and CB2.

Research ergonomic guidelines

No matter how expensive or ergonomically correct your chair is, you can still sit in it wrong, so it's important to learn what causes lower-back problems, repetitive-strain injuries and carpal-tunnel syndrome.

I recommend: The U.S. Department of Labor publishes guidelines on setting up an ergonomic workstation. You can also find ergonomic guidelines at eHow and the American Chiropractic Association.

Consider ergonomic alternatives

If you're really concerned with ergonomics and preventing repetitive-strain injuries, there are a number of alternatives to the standard office chair, including kneeling chairs, which transfer some of the weight to the knees as you sit, and exercise-ball chairs, which promote proper posture and strengthen body core (the back and the abdomen).

I recommend: Check out SitInComfort for information on kneeling chairs and exercise-ball chairs.