However I have spent a fair amount of time configuring and re-configuring things (partly my own fault, and also partly because of the learning curve involved with any new OS). I even had to do one re-install (more on that later). Mostly though it worked out of the box.
So here are a few good ground rules for newbies...
1) Make sure you have more than one Internet enabled computer in the house before you do anything. If for some reason you have a hardware conflict (as I did with the wireless card on my wife's laptop) you will need to look up how to fix it.
2) Most of what you need is available through Synaptic Package Manager or Applications > Add/Remove. If you need a program or driver search there first before the Internet. The only notable exceptions I can think of are Skype and Adobe Flash. Basically Ubuntu has a number of great free programs available which you don't need to install externally.
3) Don't mess around with settings and config files unless you really know what they do. It was this that led me to my re-install, partly because of the next category...
4) When going online for info on configuring your computer, don't automatically use the first solution you read (especially if it asks you to update your settings and config files). Manually updating settings and config files with your text editor should be a LAST resort. More often than not the GUI tools are safer. You wouldn't normally update your Window's registry by hand would you? There are sometimes exceptions, but if an article tells you to go to your terminal and do anything with sudo, vi, pico, rm or gedit think twice. The only exception is sudo apt-get install
Apart from that I found Ubuntu much faster and easier to install than any Window's distribution (way faster). Provided you have the disk or the files on hand I would say it takes twice as long to install as Vista takes to boot up on an old machine.