SEO is a very interesting part belongs to digital marketing. Its always cool profile to work but it is quite harder when we comes to show the rank in search engines. Some of the frequent search engine updates to be major obstacle for SEOs to promote their website.
You may go threw this link for further google webmaster guidelines.
https://www.google.com/webmasters/docs/search-engine-optimization-starter-guide.pdf
Building links with unrelated sites are not harmful and also it wont affect rankings. These links has no value. However building links in pornography or gambling sites will be penalized by google.
The following factors will ever hate the web site
1. Low quality back links
2. Low quality or duplicate content
3. Obvious website promotion
4. Building Link with Spam or irrelevant sites.
If your site frequently updating with unique content will help to Google to cache your site faster. Get social media signals and bookmark your site with high PR websites.
When talking generally about internet marketing, it is quite simple and effective way to reach your potential customer through online. It may be social media marketing or PPC/SEO.
Social signals are important factor to improving the website rank but not only this helps to improve in SERP. You need to do proper on page and off page SEO by following webmaster guidelines.
Do some modification according to the google's webmaster guidelines and create some useful content on your website. These are the good way to get ran for your site.