One of the greatest powers of the Internet is the ability to cross link related documents, allowing the reader to explore and learn in a non-linear fashion. Content authors must remember, however, that not all users will be experiencing their web pages the same way that the author may be. Instructing readers to click on a 'link on the right,' for example, does not take into consideration the fact that visually impaired users do not see left or right. The same holds true for references to colours or shapes (i.e. click on the 'round' button, or the 'green' text).
With the same considerations as above, introducing a hyperlink in the this manner -- i.e. 'To view a staff listing, click here' -- is cumbersome and also problematic. Resist the urge to over-explain how to a user how to use your site or the web in general. In this case, writing View a Staff Listing, with the words 'staff listing' hyperlinked than the main text, will do just fine.
Content authors must also remember to clearly describe the destination of hyperlinks in order to manage the expectations a user may have when clicking the link.
When the link is to a document in an alternative format, such as a pdf file, be clear in your hyperlink text whether the linked document holds new information or whether it is the same information from the web page presented in a new format. In doing so, users who are unable to access your alternative format document will know whether or not they are missing something important.
For example, you may have a large document that you have chosen to post through a series of web pages, and on each page you may have decided to host a link to the full document in pdf format. If it is not clear that the linked document has the same information as what appears on the web pages, someone who cannot access the pdf file (perhaps because it will take too long to download to their system or because they use an adaptive technology that doesn't work with a pdf), the user will think that they are being denied full access to the information.
Programming a link to open in a new browser window can cause difficulties with novice users for a variety of reasons (i.e. the new window does not retain the current window's browser history and disables the 'back' button function, or the launching of multiple pop-up windows may be blocked by a third-party application), and can disorient people who are using screen-reading or screen-magnification software.
The command to launch a second browser window is often driven by the idea that you might lose the client -- i.e., that they will surf off and not return. But users have many ways of returning to a valuable site, including the browser's history log, the back button, and the ability to bookmark a page.
While it is difficult to state hard and fast rules for every circumstance, authors are cautioned to create links with careful consideration of all potential users.