The most intuitive interface to SVN on Windows is Tortoise SVN.
It is a fantastic integration of SVN functions into the Windows Explorer. Right-click on folders and files to perform any SVN function.
The difference window is color-coded to show additions, deletions, and modifications, character-by-character.
The merge tool is also quite easy to use.
Although, I don't care for the name, the "blame" function shows who last modified each line of a source file, and the related revision number. I find this very helpful to determine the age of code, and the related comment of that revision's commit. Once one trsusts the version control system, one can stop polluting the source code with old commented code, and other low-value comments with dates, names, and when lines were added and deleted. All of this information can be stored in version control and readily accessed with "blame" without degrading code readability.