My kids cringed when the word "evolution" was mentioned. See, at our house, we lean toward the spectrum of young earth and creationism. It seems that my kids somehow come to the conclusion that "evolution" was bad word of sorts. This was never our intention.
This whole subject has the potential to start some quite contentious arguments. That's not where I'm going with this. All I want to say is that I think its important that my kids understand what is meant by the word "evolution" and where the disagreements lie.
See, many hear "evolution" and immediately jump to the goo-to-you concept. But, that's only one facet of evolution. Descent with modification and natural selection are also a part of the theory of evolution and I don't have any arguments with those ideas. I can even agree with common ancestry up to a point - just not all the way back to a single organism.
So, to explain these concepts a bit better to my kids, I used these two videos. Now, I did not just let my kids watch these and let it go. We watched the videos together and had discussion afterward. But, I did think they were well done. The last is perhaps more suited for Jr. High and High School due to some more advanced concepts it presents. But, both were a good, simple overview and without judgement of opposing viewpoints.
This video states what evolution is in simple language. It does go into the "we're all related to every other life form" idea toward the end - a good topic for discussion.
This video primarily talks about natural selection and I thought did a good job of describing that process. Again, a mention of the "we're related to every other living thing" idea - a good topic for discussion.
This video is perhaps better for the Jr. High to High School aged due to the way the concepts are presented. Still, a good video for discussing natural selection.