What do you need to know about links?

Q: What I need to know about hyperlinks?
A: A link is a reference to a document that the reader can directly follow. A hyperlink is marked with an anchor element, here is its most usual syntax:

<a href="http://bestseostrategy.blogspot.com/">SEO blog</a>

In the above example we have an element anchor - "a" with "href" or hypertext reference to our document – in our case – this blog. The text in the link tells the viewer or the search engine what document the anchor links. It is an optional text and can contain anything.
An anchor element can have several attributes:

• href– points to link destination.
• title – link title.
• id – the element id.
• target – this attribute is used mostly for creation of new browser window so the visitor won’t leave the current page. This is achieved through target=”_blank” or target=”_new”. It can be used also for opening documents into another frame.
• class - this is not interesting from a SEO point of view. The class attributes says what CSS class to be applied on the corresponding link element.

A link with all this stuff will look like this:

<a href="http://bestseostrategy.blogspot.com/" title="SEO strategy blog" target="_blank" class="CSSClass">SEO blog</a>

You can use images in the link or combine different html elements – for example:

<a href="http://bestseostrategy.blogspot.com/"><img alt="SEO Strategy blog" src="our_banner.jpg"></a>

A link can have an empty href, or use "#" in the place of href location (href="#"). Most of the time, these links are used through JavaScript and can’t be crawled by the search engines.

nofollow
Nofollow is an attribute used to instruct the search engines that the hyperlink must not pass any value to the linked document. This hyperlink must not affect target's ranking. It is used mostly for blog comments or bookmark websites, where the site owner has no way to track all linked resources. Example of nofollow usage:

<a href="http://bestseostrategy.blogspot.com/" rel="nofollow">SEO blog</a>

Q: How to check if a link is correct?
To check if a website links properly to you, you must see the source. Your hyperlink must have a href attribute with your site in it and without a nofollow attribute.