Video can be a very effective delivery method; however, whether you are creating your own videos or using others, it is important to keep universal design principles in mind.

First, make sure videos that are not your own are closed captioned or subtitled.
If you are making your own videos, working from a script is recommended to streamline the captioning process.
Before you embed your video, explain how you would like students to use the video: should they take notes? will they be expected to apply the information and/or reflect on the topic?
Provide the transcript of the audio as a linked file on the same page.

Resources

Presenting video content, such as TED Talks, short overview lectures or welcome messages can help create a dynamic online learning environment. The following resource can get you started:

How to Find Short, Captioned Videos in You Tube by Michelle Pacansky-Brock, CC by 4.0

You might also find this @One self-paced course helpful as you work on making your videos accessible:

Creating Accessible Captions