Even for those who are in search of professional logo on the web today you can find many services.
From companies that specialize in creative logo design, or if you do not have clear ideas, sites of logo design inspiration. There are also platforms of online logo design contest.
Alternatively there are online logo-makers as LogoFactoryWeb.

LogoFactoryWeb is a professional Logo Maker where you create a custom logo in a few seconds, even if you are not a graphic design, and download for free only if you love it!