My eyes have been opened -_- previously versioning software relied upon using text files with dates and date stamping everything. We installed subversion and trac last week and already the department is running more efficient with regards to secure updating and retrieval.
I would definitely recommend using subversion if you are working with web technologies. The ability to easily roll back to previous versions and retrieve lost data is brilliant!!
At the moment in time tortoise is the GUI of choice and is again recommended if working with windows.