Need a good advice. What file shredder is the best for novice user?

I use Shred Agent. (www.shredagent.com) It's not difficult, works in background... I didn't have any errors or issues ever...

And also it cuts temporary and cache files...

Hmm... Ok. Any other opinions?

Spybot Search and Destroy has a Secure Shredder among its numerous other features.
I bring up the files I want shredded and drag them across to the shredder - it's not an instantaneous process like Crap Cleaner, but I have it set for 13 passes as opposed to five, which is the default setting.

I use Eraser (http://www.heidi.ie) which allows you to right click any file you wish to Erase and simply click "Erase". It uses a very secure standard of erasing. It also allows you to schedule Erasing for example you might want your Temporary Internet Files erased every day, Eraser allows you to schedule this.