If you are thinking of a logo, you must already have a name for your company. My advice is to go along with the type of name you chose. Let me explain.

There are so many companies now that new companies have to be creative with what names they choose, such as 'de.lici.ous' 'squidoo' and others. If you have a name like that, (and you know your market is up for it) you can get away with a wacky logo. Generally you want to keep it down to as few colors as possible, and when you're making the initial mockups, do it all in grayscale. If it doesn't look good in black and white, it won't look good in color. (Conversely, it will look better in color).

Computers have different fonts. That means that my Mac may have a font your PC doesn't and the same is true the other way around. Keeping a standard font will help that all computers are sure to have will help later down the road when uploading a glossy logo image isn't an option. If you think about Google's logo, everyone has serif fonts on their computer, and therefore, even in text based emails and other mediums, its the same logo as their normal corporate font.

In general, do NOT use serif fonts online. Serif fonts are fonts like Times New Roman. Non serif fonts are more like Arial. The reason is, in printed materials, serif fonts are easy on the eyes and actually let you read faster. Online though, its a strain to read serif fonts due to the fact you are essentially looking into a light bulb and its easier to distinguish characters that are simpler.

Back to the logo, it really depends on what you're selling. If you are selling bicycles, and your name is 'The Best Bicycles Online' since it's a longer name, I'd use a simple font, but then to make it stand out, I'd take out the cyc in the word bicycle and put an image of a bicycle in the middle since the cyc looks like 2 wheels and the middle component.

You could also have this drawn. If you're struggling to make a flat dull logo that looked good on your business card 20 years ago look better, simply play around with adding gradients onto the image, adding drop shadows, glows, glass effects, and reflections to get a more modern look on an older logo.