This guess post at Greg Laden’s blog gives one man’s experience switching to Linux. It’s a repost from 2009, so the version numbers are a bit different (Ubuntu is at 11.10 now), but it still gives a pretty good idea of what to expect.
I would add the strong recommendation that when you switch operating systems you look at what you use carefully and check on the web for compatible options to use under the new system.
There is a learning curve for Ubuntu, but it can be especially valuable for people who need to have reasonable power at a low price. I use an Ubuntu machine as my main office work machine. I do some work on this Windows laptop as well, but almost everything I do is best done on the Linux box.