The starting point to any SEO activities is your domain choice. Ideally, you want to target some really good, highly relevant keywords within your domain name. Reason for this is that it is really easy to get ranked under your domain name keywords.
For example, owning the domain name WealthyAffiliate.com makes it very easy to get listed under the search terms "wealthy affiliate" and "wealthyaffiliate". Google naturally looks at a domain first when choosing a site that is relevant. Many times you can beat out other relevant content pages simply with a domain name and no content.
Let's say you wanted to start a website for dog training, you may want to seek out high search volume keywords within that industry like "how to train my dog". After a quick search for "howtotrainmydog.com" in Godaddy, I found that the .com and .net domains were taken, but you could pick-up another relevant extension or continue on with your search.
One cool thing here. I checked the results in Google under the broad term "how to train my dog" and lo and behold, the #5 listing was the .net domain name.
This search term gets 4,400 searches per month. At $7 per year for that domain, you are getting access to a potential of 50,000 clicks alone in Google. This is a cheap way to get a good amount of traffic before you even do anything! Say you get just 1,000 of these clicks to your site, you are getting your traffic for under a penny a click!
Choose your domains wisely...or own a lot of them as the name alone can lead to great search engine rankings.