Wikipedia defines SEO as, Search engine optimization (SEO) is the process of affecting the visibility of a website or a web page in a serch engines's "natural" or un-paid ("organic") search results.
Driving traffic to your website through SEO is one leg of having an effective website that can bring in money. Without the natural traffic that comes from SEO, the only other big traffic drivers are word of mouth and social media. Internet traffic that is driven through SEO is necessary to the life blood of website growth.
One of the plugins that I use is, All in One SEO, and is a free plugin from the WordPress site. This plugin has, no doubt, helped me to better understand SEO and how to build articles and meta tags to optimize my website.
One piece of advice that I can offer when struggling through the multitude of plugin settings or even the available plugins is to use the internet for research about the plugin and the settings. Search for unfamiliar terms and settings. Find out what the term means and research it until you are confident that you have enough understanding to implement the feature properly.
If you don't know or don't understand, don't implement the feature until you do understand.
Having keywords in your post is obviously important for SEO, but did you know that your graphics are also important. Especially when it comes to the title of the graphic and the alternate text. Search engines will scan the text part of the graphic but cannot see the graphic and it will therefore be ignored.
You also want to make sure that you are using keywords effectively. This can be a balancing act because if your content is too keyword dense the search engines will stop crawling your site. This can be reversed just by editing the content and removing the excessive density.
You do want to include your keywords in the title, and your first few lines of your article. Also make sure that you edit your first paragraph of your article to a heading of h2, this will tell the search engine that this information is important.
Finally, creating links. Linking to other sites is encouraged, especially if you feel the website you link to may have importance to the search engines. Additionally, having links to your site is important too but you cannot to go to someone and ask them to link to you unless you have an already established relationship with them.
One of the best ways that I am learning to get backlinks to your site is through something called curation which requires another post for another day.
P.S. Be sure to take a look at the Boomer Index on this site. I just added it this week and I think it will be a valuable resource for Baby Boomers.