Course building help

I suppose you have some medical credentials? You also need to worry about state laws which prohibit what a judge would deem as medical advice. Just be sure you have proper authority to teach the course's content.

Second, what is common is common. If you are offering video instruction, then list your sources at the end of each session. Also provide this list in the online portal your students use to access your sessions and/or have it available for downloading.

Assuming your reference books are medical tomes, then just use them for your own notes in preparation for your sessions. Where a specific procedure or process is particularly noted by the author or by yourself in considering how the author presents a particular course of treatment or where the author relays their own observances, experiments or trials, and these are specifically germane to your session, then you really need to provide specific reference to the tome, it's author and be careful not to pass it on as your own material.

In these specific cases, it would be customary and expected that you seek permission from the publisher to reference material in a course you are preparing.

These are general guidelines you should already be familiar with which represent best standards when referencing medical books - given it leans toward publication, all media commonly uses the print standards to whatever degree the medium can support.

Books - Citing Medicine - NCBI Bookshelf

Also this from Purdue:

When do we give credit? The key to avoiding plagiarism is to make sure you give credit where it is due. This may be credit for something somebody said, wrote, emailed, drew, or implied. Many professional organizations, including the Modern Language Association (MLA) and the American Psychological Association (APA), have lengthy guidelines for citing sources. However, students are often so busy trying to learn the rules of MLA format and style or APA format and style that they sometimes forget exactly what needs to be credited. Here, then, is a brief list of what needs to be credited or documented:

• Words or ideas presented in a magazine, book, newspaper, song, TV program, movie, Web page, computer program, letter, advertisement, or any other medium
• Information you gain through interviewing or conversing with another person, face to face, over the phone, or in writing
• When you copy the exact words or a unique phrase
• When you reprint any diagrams, illustrations, charts, pictures, or other visual materials
• When you reuse or repost any electronically-available media, including images, audio, video, or other media

Bottom line, document any words, ideas, or other productions that originate somewhere outside of you.
There are, of course, certain things that do not need documentation or credit, including:

• Writing your own lived experiences, your own observations and insights, your own thoughts, and your own conclusions about a subject
• When you are writing up your own results obtained through lab or field experiments
• When you use your own artwork, digital photographs, video, audio, etc.
• When you are using "common knowledge," things like folklore, common sense observations, myths, urban legends, and historical events (but not historical documents)
• When you are using generally-accepted facts, e.g., pollution is bad for the environment, including facts that are accepted within particular discourse communities, e.g., in the field of composition studies, "writing is a process" is a generally-accepted fact.

Deciding if something is "common knowledge"

Generally speaking, you can regard something as common knowledge if you find the same information undocumented in at least five credible sources. Additionally, it might be common knowledge if you think the information you're presenting is something your readers will already know, or something that a person could easily find in general reference sources. But when in doubt, cite; if the citation turns out to be unnecessary, your teacher or editor will tell you.

source: Purdue OWL: Avoiding Plagiarism