Internet Marketing works closely with Search Engines. For Search Engines to properly index you, you want to use proper SEO tactics and that includes making sure that your keywords are included on every single page1.
A keyword is a word in the language you write your website. It can also be a small group of words such as Snap! SEO or Snap! Blogger Free. As you progress, you will find out how to tweak your keywords. It is okay if you start with a slightly wrong set of keywords. It is quite usual for a newbie to make mistakes!
This first step, you generally have to do it yourself. The number of keywords you want to use in your website should be limited to about 20 keywords.
To determine your keywords you want to know what you will be talking about on your Snap! Website. Say you are going to talk about car motors, then finding 20 things that people will most certainly look for in regard to car motors is what you want to write down. For instance, it could be the words injection and carburetor.
Note that search engines are smart enough to know the plural and conjugated forms. So carburator and carburators are considered to be the same word. Similarly, have am has had hath having are considered the same2.
Now that you have keywords, you need some means to learn the ones that are the most important ones. In most cases, you want to limit yourself to the three most important keywords.
So... The best way that the professionals use to select their keywords is to go to Search Engines and query their data to know which of your keywords are the hottest. The best tool for this purpose is Google Adwords: Keyword Tool3.
The one number you are interested in is the total number of searches there were in the last 30 days for each of your keywords (if you are working for a local business, use the number under the Local Searches column.) In general, the higher the number the better, although a count of more than 20 million will generally not help you because that represents a lot of competition. So at the beginning, you'll have to settle with keywords that have a number of searches between 2 and 3 million instead. It is not forbidden to use any keyword, it is just important for you to get results sooner rather than later and thus avoid harsh competition on day one.
For instance, the word carburetor was search 550,000 times in the last 30 days. This is thus a really good keyword for your website talking about car motors.
Once you determined your keywords, start using them everywhere on your Snap! Website. All the different places of interest are defined in this documentation, but anywhere you can place then, do so.
Obviously, although they should appear pretty much everywhere, make sure that you don't over do it. Think about the result if you were one of your readers... would you like to read your own website? If the answer is No Way! you've got something wrong.
Keyword stuffing is actually a very negative aspect of SEO and it can cost you points on your rank.