[TYPO3] A question about lay-out

[Nader Emami Salut]

Hello,

I am a newbie in Typo3 world. It is almost 2 weeks that have got 
acquainted with "typo3". I was sure whether I would use "Plone" or 
"Typo3", but I have decided to use Typo3.
I would setup a CMS for our group and would like to use the same layout 
as of "typo3.org". Would somebody give me some indication about it? 
Where can I find documentation of other things?

With regards,
Nader