Thorough HD clean

Hello, after over a year of having our PC the time has come to do some serious hard drive cleaning to improve performance. I've looked on the internet about doing this but all I can find out about is the Temporary files so I thought I'd come here. Has anyone got a tutorial/links on cleaning out the hard drive so there's no more junk/files.

Any help would be appreciated.

Cheers, thesim.

 

Here is a good cleaner,

http://www.majorgeeks.com/CCleaner_Slim_No_Yahoo_Toolbar_English_d4191.html

 

I've already got that I need a more thorough cleaner for normal files like documents or pictures. Like a small pie chart showing me where all the files are.