Links

The General rule is the more the better, but it's more complicated then that. Where the link comes from and where it pioints too are equally as important.

Quantity
How many links point to you.
The basic math is the more links you have the more value Google gives your site. It basically is seen as a vote for your website

Quality
Where are the links from.
But the Basic math is does not cover the Quality of the link or what the link says. What this means is that not all votes for your site are treated equally, If you the florida of web sites your vote does not hold the weight of a super delegate.

Several factors are at play here:
The site the link is coming from, the page it comes from even the surrounding text is important, but most crucial is the actual text that links to your site

This is covered in more detail below (Anchor text and Surrounding Content).

Quantitude
Where they point to.
Yes having a link from an important site point to your site is good, but if it points to the wrong place your losing some of it's value. Having all links go to your home page is not a good idea, our inernal pages are usally more relvent to aterm then the home page. This is known as Deep linking.

The general Rule is that 1/3rd of your links should point to your home page while 2/3rds point to intal topic related pages.

Anchor text and Surrounding Content

As dicussed above having just alink to your site is not even half the battle.

Anchor text
The anchor Text refers to the actual text that is hyperlinked to you web site. This should be rich with keywords so that the link vote is tranformed into a vote for a specfic topic for your site.

Paragraph
Relavence of paragraph content surrounding the link is as important as the link text itself, This lets google know that it is just nota paid link but actual content about a subject and that you page has more conent about that subject.

Page
Relevance of page content. this reinforces the same issue as the paragraph, the more related the page is to your page the more vote power gets passed with the link.

Site
Relavence of page site. Finally the site itself if this is on topic, to your page then thelink is even more valuable.

Combine all these element and your link is very pwoerful a virtual super link.

Warning:
Using the same backlink text phrase on everylink is a sure sign of link manipulation by Google and could result in penalties and the values of those link reduced.

Types of links

So you have yourself a certified super link, your feelign smug but wait you can still be trumped. You didn't factor in the authoirty of the site linking to you.

Site Authority of link
All sites are not made equal, in Googles eyes, You may have the right page topic and anchor text but if google does not like the site, then your vote is not goign to be as strong as it could. A cheap and dirty way to check is check the page rank of the site and of the page the link is coming from.

Having a link from a .org or .gov site is seen as trustworthy and also helps increase the power of the vote.

Directory
Which Directories link to you.
A direcotry is usallya good link as it has a revelevnt anchor text and paragraph and often a strong theme to your site.
Yahoo and Dmoz or the big 2 directories that have value to link to you,
You also want to look at industry Directories, for example a directory of florring experts would be a value place to have a link if your site was about carpet installation. Likewize Local direcories are very valuebale for addeding local vote power to the website.

Here is a list of all the directires we submit too at dda

Reciprocal
Do you have reciprocal linking. At one point this was an easy way to get links. You link to me and i'll link back to you. This has been greatly reduced in value now as Google knows if 2 sites link back and forth.The value of that link vote is reduced.

There is a way around this using the "Ménage à trois" method:

A links to B, B links to C and then C links to A, but like the real thing is not easy to convince all parties to pull off this maneuver successfully.

Unsolicited
How many unsolicited links point to you.
These are both the easiest and the hardest links to get, as you get them with out asking but you have no control over the link of if you get one.

The best way to get these is with "Link Bait"

Linkbaiting is a term used in Search Engine Optimization to describe numerous ways to generate incoming links. Because there are so many ways in which linkbaiting can be used it’s actually a hard word to define.

A good way is to describe a number of linkbaiting techniques.

1. Quizzes Contests and Surveys are a great way to get people to participate in your site and in turn link to your site to show their participation or encourage their friends to beat your score on your quiz.
   
   
2. A cool tool: If you create a useful tool for your industry not only will your traffic increase as people utilize it but it will naturally attract links too.
   
   
3. Scoops — If you are first and have a breaking news article or can expose a fraud in your niche.
   
   
4. Awards — Give out awards to website/blogs in your field.
   
   
5. Controversy — A risky one, but done well, a risky article or post can create hundreds of incoming links.

Overall Linkbaiting is good for your site in two ways — it generates more direct traffic and then it increases your links,  which in turn improves your search engine ranking.

Paid
How many paid links point to you.

Paid links are now generally frowned upon by google, this is the practive of paying a popular site to ad your keyword link to it's pages for the purpose of gaining page rank on your site.

Google has been known to activly reduce the page rank of sites that sell these types of ad, reducing the value of the link you are getting.

Social Media Presence

Social bookmarks
How many social bookmarks do you have

Blogs
Do you have many blog links