Hello everyone just an addition of the previous Backlink topic.

As mentioned earlier backlinks are very important to alert search engines. The more backlinks you have, the higher you would be placed in the search engine results for the relevant keyword.
However while you are acquiring backlinks, you will want to be sure that the site is a "Do follow" site. A "Do Follow" backlink is a standard incoming link that does not have the "No follow" attribute.

Question: What is a “No Follow” or a “Do follow” site?
A site with a “No follow” is alerting search engines NOT to follow that link while crawling the website. At all times we would want to create a backlink in a “Do Follow” site. There is very little benefit from “No follow” sites.

Question:How to tell if a site is a No follow or a do follow?

Many ways let me show you the basic way
Step 1: Select "View" and then "Page Source" from your browser's menu bar.
Step 2: Click the "ctrl" and "F" buttons at the same time to launch a search of the source code. To find out if the site uses nofollow at all, use "nofollow" as your search term.

A better alternative:
I use SEO quake Firefox plugin you can download It here
https://addons.mozilla.org/en-US/firefox/addon/3036
Once you have determined whether of not a site is a “do follow” or “No follow” you would want to leave a backlink to that site.
Question: So there is totally no benefit for creating backlinks at “No follow” sites?
Well I wouldn’t say totally no benefits but the benefit is very minimal to post at a NF site, since you won’t get any backlinks, the only thing you would benefit is when someone reads and clicks on your link. A backlink at NF sites will not help your Search Engine Ranking.

To create backlinks always try to use your targeted keywords in the anchor text of your backlinks whenever possible.
Here is an example: This would be a normal link   http://www.yourhealthfoodstore.co.uk/
An anchor text would be something like   Nutritional drinks

Question: So what anchor text should one use?
The anchor text you should use varies with what you’re promoting but for this example let’s use the Acme People Search program.
Try to use Achor text like
1)    Acme People Search
2)    Acme People Search program
3)    Acme People Search Engine
4)    People Search Engine affiliate
5)    Make money with Acme People Search
The reason for diversifying is for it to look more “natural” in the eyes of the search engines. There has been a lot of debates on whether getting backlinks with the same anchor text would be deemed natural or not and whether search engines will penalize your site for not looking natural. No one knows the answer for this but to be on the safe side just diversify your keywords.
You would want to diversify but at the same time you do not want to overdo it. Keeping to some of the main keywords should be good.

So in summary
•    Try to get links from sites that are related to your niche
•    Always try to get backlinks from Do follow sites
•    Diversify your keywords in your anchor text whenever possible
•    Try to obtain links in a more natural way, i.e don’t over obtain links

Top 10 Article directories based on Alexa rankings
Note the NF (No follow!) for no 2,6, & 7
1.    ezinearticles.com    
2.    articlesbase.com    NF!
3.    buzzle.com    
4.    goarticles.com        
5.    helium.com - (I can't seem to figure out how to submit an article in helium)
6.    articlesnatch.com    NF!
7.    articlealley.com    NF!
8.    articledashboard.com    
9.    ideamarketers.com        
10.    amazines.com

Hope this helps!