Menu background is repeating, i think because of login button. It would be better if you fix the width of infolinks related tags under the menu.
Looks quite professional, lot better than many other bookmarking sites. I would improve the logo a bit,
I think the header section has too much height. Content starts way down...maybe you could shrink it a little so that your visitors can check latest content more easily.
I think it's a well put together site. Maybe start content more towards the top of the page as powerdude has stated.
Honestly, it's just plain confusing. Try using a simpler theme. Less ads, also. It'll look more legitimate and less spammy that way.
I have an ad that`s enoing ! A pop-up ! I also don`t like the ads placed under the menu in header ! In rest, good job !