It all depends on what kind of site you want to build.
If it is simple personal page it could be very easy. There is a lot of free template and designs which you could edit to include your content.
Still you should know some basics of at least html and css.
You can google anything on this subject it should be well covered on the net.
Unfortunately most of the guides and tutorials seem to be commercial or just there to sell you something else.
One of the free and well organized sites with tutorials is:
http://www.w3schools.com/
This one seems worth checking as well:
http://www.entheosweb.com/
or this one:
http://www.htmlgoodies.com/
There is also a lot of website building software that enables less advanced users to easily create a website design and fill it with content.