tl;dr Nothing. goto http://www.logodesignguru.com/ http://www.logodesignguru.com/ http://www.designmantic.com/ http://www.designmantic.com/ http://www.logom

tl;dr Nothing. goto http://www.logodesignguru.com/ http://www.logodesignguru.com/ http://www.designmantic.com/ http://www.designmantic.com/ http://www.logomaker.com/ http://www.logomaker.com/ http://www.logogarden.com http://www.logogarden.com And, as added value... My personal experience is that Logo Design (and upkeep) is a low priority, but should always be an active priority. Keep in mind where your logo will be used (web, print, swag, etc...), and don't be afraid to work on a new design, you may have been off the mark with your original design. That said content trumps design a lot of the time, unless the design is super bad, then it gets in the way of your content.