If you believe that Murphy was an optimist then the following is for you.
Let me say again that this is not a "requirement" BUT if you have been having problems (there are never any problems with a Mac are there?) or if want to be sure of not loosing anything and being able to restore your old OS then this should give you the best chance.
At a minimum I would have a full backup before any "major" upgrade. But all of you are backing up all the time already using Time Machine, right? If you are running OS X and Time Machine you have OS X Recovery built in. However, OS X Recovery will ERASE your disk before it runs. Time Machine does not back up your entire hard drive but Carbon Copy Cloner does. Accept no substitutes.
So here goes:
According to the latest reports, 40% of Mac retail sales are represented by 'switchers.' It would be safe to assume that another portion of Mac sales are made by users new to computers entirely. Last time I checked, Macs come with a rather bare bones instruction manual, if they come with anything at all. While most of us feel OS X is designed so well, it is self documenting, not all users have such an easy time. Most of the readers of MacVolPlace probably are well beyond these types of tutorials. But I get questions all the time from switchers who want a resource to get them over the initial speed bumps of the change. Rather than pulling your hair out, take a look at these sites: