The Internet is filled with free and easy resources for you to link to within your e-Learning. It's tempting to reuse much of this material rather than recreating it for your on-line learning. In fact in these busy times, it makes sense to do so. One of the steps that is considered an accepted part of the design and development process is to determine if training already exists elsewhere. The notion of not reinventing the wheel is of course an an axiom. That said linking to an external source of content creates much risk, and I caution any one considering this. Below are some of the risks to this practice for you to consider before making your own decision.
Dead Links
An obvious issue is the risk of links that go nowhere. Everyday, thousands of web pages come and go. Just because you may have found a particular page of content to be beneficial, doesn't mean the original author or their service provider will maintain it for you. In theory you could monitor all your links on a daily basis to ensure the integrity of your e-Learning, however most Instructional Designers just don't have the time. While linking to outside sources of information may save some time initially, may cost you additional time later when you have to repair your course for it's possible dead links.
Learner Compliance
Many organizations can still be challenged to get their learners to log in and take training in the first place. Adding links to external resourced may distract their learners and discourage the learner from returning and completing their online modules. As an Instructional Designer, it makes more sense to absorb the knowledge yourself and then incorporate it into your course. If you find a really stable and useful site you wish to share with your learners, put the links at the end of training as an additional or optional learning.
Author's Permission
Although linking to a site is considered the best and most ethical way to reference another's work, it doesn't mean the original author will agree to its use for your training purposes. There may also be bandwidth restrictions put in place by the author's service provider. Adding your 10,000 learners from your organization may exceed the expected bandwidth and cause problems for the original author. Others just may not agree with the organization you are apart of and therefore would not want their material to contribute to your learner's development. Whatever the reason, this may become an issue for you and subsequently the original author. Consider this before using their work.
Quality Control
This is the one area where I got burned and inspired me to change my mind about external linking. Ironically I was only linking to my own organization's web site. I thought I was very clever in that if anything changed about the content, my training would be updated by default. Unfortunately there was a spelling mistake on the page I was linking to. Even though I was not responsible for the spelling mistake on the corporate site, it did affect the quality of my training and therefore I had to shoulder some of the blame. I was lucky it was only a spelling mistake though. The web is outside your control and very colaborative through the use of forums and comment pages. You may end up linking to a page promoting a belief that is against the values of your organization or maybe even something worse.
Now I will break my own rule here and provide you a link to the Rapid eLearning Blog that has a great related article on the 10 Things to Consider Before Your E-Learning Goes Live.