NEW!! How to RE-INSTALL EVERYTHING so the macbook is like NEW!!!

Hello guys, I had some questions about making my macbook (Black) Like new.
*I know that someone else had a post about the same matter, however, i was still confused*

*I'm a new Mac user, my first mac computer ever...congratulations to me huh?!? Hope this is a good machine.

Well, the previous seller had used it for around 1 month but had to sell for whatever reason i shall not disclose. I received the Macbook today and turned on the macbook. However, a screen comes out with login and password, which means this computer is customized to the previous owners likings.

I have the CD which came with the macbook, all in the box, but dont really know how to cLEAR EVERYTHING...i mean EVERYTHING the previous owner had in there and make it like i just bought it at a APPLE STORE NEW!!! Please advise at your convenience. Thank you guys, and wish me luck with my 1st apple computer. THANKS AGAIN

Insert the Restore CD, and reboot the computer.When you get to installation options, select erase and install, and let it completely install, then it will be like it was when it first came out of the box.

Make sure you hold the "C" key to boot from the CD, then follow StretchR's directions