This topic like most topics on this site is meant to be kept simple and when it comes to keywords when developing the content for your website be sure you keep your selection simple as well. Keywords are the words that you would think other people use when performing searches within a search engine such as Google or Bing. With enough imagination a person could come up with just about any number of combinations for use as a keyword but be sure not to overdo it.
If you are cramming thirty to fifty or more keywords into a single page of copy you will not get the results desired. Also while it is good to repeat your keywords within your copy you should also be careful not to repeat them too often within the same page or paragraph as you might be tagged for keyword stuffing. I wish I could tell you the correct ratio of keywords to copy but as with anything on the world wide web that golden ratio is always changing. A well thought out selection of keywords positioned well within your copy and repeated sparingly will net you a great return as far as search traffic.
You cannot just post something great into the wild and expect a random search engine spider to come across it and consider it the greatest morsel it has ever eaten. If your not listed within search engines and just starting out a great thing to do would be to ask friends or business partners if they could post a link to your site or the new content you have recently created. Another venue for copy crumb consumption could be that of social media. Social media today is all over the place and a great way to let people know that you have something they should read and hopefully provide propagation of your tasty morsel. Most common social media sites include Facebook, twitter, and Stumble Upon.
You can also submit your site or content directly to search engines but from what I understand this is normally the slowest way to get your site noticed and indexed.