Documentation is a set of documents provided on paper, or online, or on digital or analog media, such as audio tape or CDs. Examples are user guides, white papers, on-line help, quick-reference guides. It is becoming less common to see paper (hard-copy) documentation. Documentation is distributed via websites, software products, and other on-line applications. 

Professionals educated in this field are termed documentalists. This field changed its name to information science in 1968, but some uses of the term documentation still exists and there have been efforts to reintroduce the term documentation as a field of study. 

While associated ISO standards are not easily available publicly, a guide from other sources for this topic may serve the purpose. . David Berger has provided several principles of document writing, regarding the terms used, procedure numbering and even lengths of sentences, etc. 

The following is a list of guides dealing with each specific field and type: 

The procedures of documentation vary from one sector, or one type, to another. In general, these may involve document drafting, formatting, submitting, reviewing, approving, distributing, reposting and tracking, etc., and are convened by associated SOPs in a regulatory industry. It could also involve creating content from scratch. Documentation should be easy to read and understand. If it's too long and too wordy, it may be misunderstood or ignored. Clear, Short, Familiar words should be used to a maximum of 15 words to a sentence. Only gender hyper neutral word should be used and cultural biases should be avoided. Procedures should be numbered when they are to be performed. .
Do people get educated for this?
Professionals educated in this field are termed documentalists