Philipp Lenssen's recent 11 Link Usability Tips reveals a pretty good guideline when coding the links in the web html page, which was claimed as The art of hyperlinking by Jeff Atwood.
- Ensure your links are large enough to easily click.
- The first link is the most important one.
- Don't link everything.
- Don't radically alter link behavior. Very good point that I don't follow all time but will be from now on.
- Don't title your link "Click Here".
- Don't link things the user might want to select and copy.
- Don't include icons on every link.
- Don't make your content depend on links to work. Good point too. Not everyone will click on the hyperlinks. Either they're too busy to click every single link you put in front of them, or maybe they're reading your article in another format where they can't click on the links: print, offline, or mobile. Either way, it's important to provide the context necessary to make your content understandable without the need to visit whatever is behind those hyperlinks.
- Don't hide your link. Give them a distinct style, or underline them all time.
- Don't mix advertising and links. Single-underline is for the hyperlinks while double-underline is for advertisements.
- Don't obfuscate your URLs.
Jeff also mentioned that Keyvan Nayyeri's Simplify your URLs would be a fantastic starting point. And using DecentURL to polish the ugly URL.