I firmly believe that Macs are superior to PC’s, but I freely acknowledge that there are differences between the two that take a little getting used to. As an easy example, Macs have an "Option" key that I regularly use, whereas PC’s don’t. Other differences come in the form of naming conventions — Explorer on Windows translates to Finder in OS X.
Fortunately, there are many resources to help assimilate this new information, including A Switcher’s Guide to Windows and Mac Differences and Equivalents. This resource provides a list of the equivalent terminology, way of doing things on a Mac, and applications to use for PC converts. Even better, it includes several tables which make it easier for you to relate the relevant methods between systems.
Source: "A Switcher’s Guide to Windows and Mac Differences and Equivalents" by Chris Howard, published at AppleMatters.