Designing a logo is no easy feat. Many think that just using any old font and symbol will do, those are the logos which aren't usually very memorable. It's why most logos are absolute crap. If you walked down your local highstreet now and looked at the logos which shops are using, you'll find most are actually crap and have been put together without much thought at all.
This very neat infographic by sothink.com shows you how to get inspiration from logos already out there.