OK, here goes....
I would consider changing the page title to Unix, your ads don't appear to be very well targeted, for example do a search on google for unix and see all the unix ads, then do a search for unix articles, no ads! You could also use section targetting to further target your ads.
You have one 336x280 ad block at the top beside some content, move the content down, and replace it with another 336x280 block so you have two side by side at the top, then change the color on them so they match all the other text on your site, blend them in rather than make them stick out.
Next, put a 5 link link unit in the top left where your categories are now, I would move the categories over to the left navigation area, and then put another 120x600 skyscraper right below the link unit.
Replace your search box with a google search box, also consider putting a search box bottom center of your page.
This is maximum you can put on there according to adsense tos, and will give your users many more ads to click on, more targeted ads, and should put your ctr in the 30%+range.
Repeat on all interior pages.