Although the main goal of this website is to get community help for editing closed captions to open access videos, it would be even better if the creators of these videos provided edited CC to start with (and also made sure OA items are accessible in other ways). The University of Nevada, Reno has a good website that provides resources on how to make sure online content is accessible; feel free to give it a look. Check out this web accessibility primer from W3C. And read how to use crowd sourcing to edit the closed captions on your own YouTube videos. Got another resource you find helpful? Let me know, and I'll add it.
Also, here are some tips I found just by doing this myself:
For those who want to edit the CC of videos created by others and posted to YouTube: YouTube doesn't give you the option to download videos. You have to download/install a separate program to allow you to do this. I use Video DownloadHelper, which is an extension for the Firefox web browser.
When downloading videos, choose the highest quality version allowed that does not include "ADP." I don't really know why; this is just something I was told by one of our guys in charge of this.
When uploading videos to YouTube, know that it can take a while for it to create the auto-generated CC. This can take several hours, especially for longer videos.