NOTE: THIS ARTICLE HAS AN UPDATE AVAILABLE HERE
The number of people I see posting on forums asking for support on components who are running versions of Joomla! sometimes 4 or more versions out of date is really quite alarming - when I point out to them the error of their ways, often the first question is "Well how do I upgrade to the latest version?". Hopefully this article should help clarify the process involved with installing the latest patches for Joomla! and help you stay up to date!
Joomla! docs has a full walk-through of this process, which is where most of the information in this article is from.
