Building my own WordPress theme

Hey guys, I’ve just started out on the long process of building myself a new portfolio site and want to create a blog that’ll run along side. This is mainly for my own use as a live referencing page.
I’ve designed a very simple layout i want to build but just wondered how easy it will be to do? I’ve installed WordPress on my site so everything’s in place to start just my css skills are very basic. Is there any good places to find guides on easy build? I’m quite willing to get my hands dirty and learn as i go…..

Many thanks!

Example