On your design: don't use pt for font-size. That's a printer format, not meant for the screen. I use em's and % myself. That way the font's get scaled compared to the size the user normally has on their screen, which makes it always legible if you don't go below 1em or 100%. On your site in general: your implementation of adsense is alright for now. Worry about getting good content on all pages you have links to first. I clicked on several non-working links. Visitors first, income later. When the site is fully functional, and you get about a 1000 visitors a day on it, go about optimizing your adsense. I agree with previous comments that having one big block on top is probably enough for now. The one on the bottom is likely not getting too many clicks.
I would suggest you tou use any ad format but dont make your site ADSENSE-ONLY site. Visitors dont like too much ads, I will say to increase your CTR in long run you need returning visitors and they only come if they get good content, less ads and fresh updated content every time. Thats not all