Atomicorp

Hello
I am searching a CMS. I found a lot on google and i cant decide. Maybe some users can give my some hints what is good.

What i need?
I need a CMS. I want to create some articels und Tutorials for my little website! I want write so 20-50 arctiles in 8 category! I dont want that other other can register. Only me!

Can someone help me to find the right php software for free?

I kind of like wiki's myself.

I have tried ExponentCMS and Joomla. Joomla is very supported with alot of users around the globe. Exponent is nice, but kinda hard to get support...