Links

How to Link

HTML

Use the Link button

Make it obvious where the link leads

Contrast

Encourage flight?

Sidebar

What to Link

External links

Related content

Internal links

What not to Link

Punctuation marks

Headlines

Why to Link

Credibility

Site traffic

Interactivity

References

http://webdesign.about.com/od/beginningtutorials/qt/external-links.htm