Use of external resources as teaching aids I am teaching a course in calculus.  Things are generally going quite well, but since this is the first course I've ever taught I'm certainly not doing a perfect job.  As a result, I sometimes come across lecture topics that don't go so well, either because:


I didn't do a good job of explaining in lecture, typically because I made a mistake or glossed over something or
The concept itself is just difficult, and requires a lot more time to understand than I can devote in lecture.


In these situations, I make sure that I communicate to the class that there was an issue, and I often look for or create resources like video lectures or supplementary documents that clarify things. 

If I want to be 100% sure that the message I deliver is in agreement with how I'm teaching the course, I make the material myself.   For instance, if there are multiple, conflicting definitions of the same term, I tend to make my own material and post it for the class in order to ensure that my definitions are consistent throughout my entire course.  I've done this several times and my resources are well received.

However, there are resources out there that are just clearly better than anything I can whip up, at least in the time I have.  Khan Academy is particularly fantastic and has great videos, activities, etc.  Rather than re-invent the wheel, I will provide links to these resources when the topic is either not critical or where the resource aligns very well with how I've taught the concept in class.  I always make sure to properly give credit and do not take credit myself for things I did not create.

I'm not sure why, but somehow this feels like "cheating". I'm also concerned that it will be perceived as laziness on my part by the students.  So the questions:


Is this cheating? Should I be making my own material, in order to 100% guarantee that what my students see is consistent with how I'm teaching it?
If not, is there anything I should be doing to ensure that students understand that these resources are just one part of the course, and shouldn't be exclusively relied on?
Giving an extra resource from another properly referenced and acknowledged source gives an explanation with a different flavour - I do this and so do my colleagues - do all students use or appreciate - no but some do, so it's worth it. Best of luck you have a good attitude.