Monitor Calibration:

Discussions related to monitor calibration and the implications it has on your photography. Examples: how you calibrate your monitor, calibration devices, problems you may have calibrating your monitor, etc.

If you take your photo viewing and editing even moderately seriously you need to calibrate your monitor. This may be the first and most important step if you plan to color manage your photos. I avoided this initially, but after some printing and viewing my photos on other peoples monitors I soon realized it's importance. If you're going to edit your photos for color correction don't even bother if you haven't calibrated because corrections you make most likely will only look good, as far as color goes, on "your" monitor.

Here's a few clues pointing to the realization that you need to calibrate your monitor:
1. You print your photos at home, send them out or have them printed at your local store print service and the colors just don't look right.

2. You send a friend a photo via email and you get a response with the question "Why is the sky purple?"

3. You post your photos online and EVERYONE wonders "Why is the sky purple?" (Some people do know why and so will you!)

4. You decide to tweak your monitor colors a little so the photo you're working on looks more real only to find that the colors in all the previous photos you worked on now look out of whack. (out of whack-technical term for crappy, color-wise that is. Fairly new term, you probably won't find it Wikipedia yet.)

5. You submit your photo to Sky and Telescope for publishing convinced that "you" of all the photographers in world have photographed a blue moon. You get a response saying thanks they already have some but you may consider submitting to a magazine doing an article on color management. 

Monitor calibration methods:

There are many factors that can influence the colors in your photos but for this post let's stick with calibration. There are a couple of ways you can calibrate. The first one is calibrating by eye. It's better than no calibration but not the "best" way to adjust color. Our brain has it's own calibration scheme and it can fool us because it adapts what we see to what we think we should see, if that makes any sense. You can search the web and find any number of sites that have free color adjustment tools and images for eye calibration. Another way is to print a photo or have a photo printed, compare it to your screen and adjust your screen colors accordingly but this approach can be specific to a given printer (whole other post on that) and most likely will not provide consistent results. The best way to calibrate  is with a monitor calibration device.
Selecting a monitor calibration device:
There's a few main companies out there that make them. Which one you purchase will depend on your budget and your requirements. Since I never had seen a calibration device I was reluctant to spend a lot on my first one. Setting a budget at $100 or less narrowed it down. After researching I chose the Spyder3 Express (link to read users reviews at Amazon on the sidebar).
Using your calibration device:
It's really pretty simple to use.In this case my Spyder3 Express. I'm usually a little intimidated by new things but if you just jump in you'll see the waters fine.  You pretty much just install the software and it guides you through the process. It asks that you warm up your display for half an hour prior to calibrating, check that there's no direct light on your monitor, adjust your monitor settings (contrast to default, brightness to what's comfortable and if your monitor offers a Kelvin setting, set to 6500),  plug in the Spyder3 unit to your USB port. You basically hang the cord with a small attached weight over the top of your monitor with the unit resting on your screen and press "next" and your display will start emitting colors and the Spyder3 will record and adjust the monitor color and create a profile automatically. When its done hit "finish" and the software will display before and after correction photos so you can see and compare the difference from the calibration and then select "finish". That's it! Your monitor is now color calibrated. You almost certainly will see an immediate, pleasant improvement in your displayed colors.
Is it worth spending more?:
This reverts back to your requirements. The more expensive units will adjust gamma which basically refers to image brightness, allow for more control of over profile settings, and allow you to calibrate your printer, projectors and televisions. I haven't used more expensive units yet but would like some input from others regarding their experience with the these other models compared to less expensive ones. I just want to say that calibrating my monitor at this level has provided a major improvement in the sharing and printing of my images.