Who should you use them?
Anyone who is trying to attract visitors to their website or blog through search engines should use keywords to increase their ranks.

What are they?
Keywords are popular words and phrases used when searching on the Internet. For example, if you are looking for information on getting your dog cleaned up, a keyword phrase might be dog grooming.

Why use them?
When you go to Google and type in your search, you use the keywords you think will lead you to the information you are looking for. Websites use keywords in certain ways that make them appear higher on the search result pages. Keywords can be the difference in your page ranks.

When do you use them?
All the time. Just don’t be extreme about it. Don’t make up opportunities to use keywords. Don’t use keywords for animals if you are writing a blog about boating. If it makes sense, do it. Go easy on comments on other people's posts though out of respect and because it is a waste of time.

Where do you use them?
Basically, you use them everywhere, but DON’T go overboard!
     - in the text on your web pages or even the title of your web page or blog. Make sure to keep it related though and don’t put keywords in if they don’t make sense. (Try to get rid of the word “thing” and you will use keywords)
     - image captions or alt text
     - in the HTML code of your site, use the head tag for keywords (see how for Dreamweaver CS4)

Where do you get more keywords for your website or blog?
I have a few places I like to go to get more keyword ideas. Some resources cost money and others are free. I’ve never paid for my keyword research but I know some swear by it. Right now, I’m going the free route. I use Google Adwords Keyword Tool and KeyCompete.com (affiliate link).