The first thing you need to realize when talking about current SEO (Search Engine Optimization) is that what worked a few years ago still works but it needs to be modified to comply with the guidelines of the search engine you're expecting to rank your site on. For most of us looking for the top traffic source, that's Google.
OK, while there is a new methodology you must use if you want Google to like your site, some of the old methods are still as effective as they always were. The primary tactic here is getting backlinks to point at your main (or money making) website.
In the old days (pre-2012) you could unleash high numbers of these with relevant anchor text related to your keywords using software and your site would magically outrank everything else. Now you have to work a lot smarter to stay within Google's quality guidelines and that means no more spamming links!
Article Submission for Links
You can still submit articles to directories and article submission sites, each with a link to your money site but nowadays, those links should be non-committal and definitely not containing your keywords. In other words, the anchors need to be bare url, site name or brand, generic (such as "click here", "this site" etc).
This is to avoid falling afoul of the Penguin algorithm that counts links and their anchors and penalizes sites that go over a certain limit (which is unsurprisingly strict). You should also try to get links from sites that are relevant to the topic of your site if you can (although generic article directories are general but that's OK).
What this does is build a non-threatening link profile for your site that will not trip any red flags or cause any penalties. It's still a good idea to get the links slowly, like in a trickle rather than in a flood. But over time you can end up with hundreds or even thousands of these and you're site will only benefit from it.
Getting Good Links
Once you've built up a strong neutral link profile, you can start adding links with your keyword as the anchor. But do this very sparsely and don't use exactly the same anchor more than once or twice.
The idea is to stay under the radar and avoid any threat of a penalty now or in future updates to the search engine algorithm. In other words you build in future-proof authority for your site.
Where do you get such links? That's the problem many site-owners face and most end up paying thousands of dollars to SEO companies to get those links for them.
But you can do it yourself for zero monetary outlay (but at the cost of a fair amount of your time) if you want. Or very cheaply if you want to outsource some of the donkey work.
Here's how to do it for zero financial cost:
Getting Free Backlinks with Power
What you need is access to some websites that are both totally relevant to your money site and under your control. You can still do guest posting but there is a risk the owner of the blog night take down your link and keep the content you gave them for free.
But the best way is to use fairly web 2.0 properties you build yourself with a single decent article. You create a mini-site or mini-blog using one of the top web 2.0 sites like weebly, webs, wix, blogger, wordpress, tumblr etc with related keywords in the url (site name) and with a big long article that's right on topic for your site that is NOT rubbish (ie spun or very badly written gobbledegook).
You Must Be Prepared to Put In the Work
This is where you need to spend some time, but it pays off. You publish your article on your web 2.0 and put a keyword targeted anchor backlink in there.
Just include the one link to your site that you put first in the article. Near the end of the article, add a link to a related article on an authority site such as Wikipedia, a news site, government paper etc. Then publish, ping (I use ping-o-matic) and send some social shares from Facebook, Twitter, G+ etc.
Your web 2.0 will index pretty fast if you do all those things and your link will count for way more than hundreds of spammy links. That's how you do it for zero cost!
When your money site starts generating more income, you can use some of it to pay for outsourced articles and web 2.0 creation using fiverr or even go to the next level and start buying and hosting some of your own domains (see: davidmazer.com). But that's the topic for another article.