New User Questions

I have some experience with admin of an existing WordPress set created by others. I have done a fair bit of work on the site over the last 4 months. I have also recently created a website using Dreamweaver. Appx 15 pages, custom forms and etc. So, I’m not an expert but I have some experience and I’m used to learning as I go.

Now I want to create my first WordPress site. I have wordpress installed and working correctly on my computer. I have made a mockup of the site I’d like to produce. See the link below.
my click thru mockup

My question – Is this type of site layout able to be produced using WordPress? I was thinking of trying to modify the Twenty Ten Theme to achieve this. I’m right away finding uncertainty about how to have clickable links in the header. And how to control the positioning of images and other elements on the page.

I used html and css for structure and positioning in the site I made in Dreamweaver. The css that controls the WordPress theme doesn’t seem to offer that kind of page by page customization.

I know this is a broad question. I’m hoping to get some advice as to if what I want to do is possible/advisable? Would I be best to learn how o create my own theme for this or is tweaking the Twenty Ten theme a viable strategy?

Thanks for any help or advice!