Starting out can be tough. Experience and observe the company/department/team you are seeking to organize and structure the knowledge for.
* Do they care about capturing, authoring, presenting and maintaining knowledge? How much do they care?
* Enough to insert steps into their existing processes or create new ones?
If so, you have a chance. Otherwise, focus on organizing and structuring YOUR OWN company knowledge. When others look over your shoulder at a meeting, read your notes, your reports, your guides, you may be able to entice.
Examples speak louder than words.
Tooling can be tough. If you work in a small outfit, you can likely spin up the best KM tools available. If you work for a dinosaur, good luck. They are likely already entrenched with some sharepoint mess that busily employs 10's if not 100's of people. Bringing your "new tool" to the IT department will get you the run around. (I've been trying to implement Gitbook (my fav KM tool) for over 1.5 yrs.).
Large companies may also have problems with cloud deployments. And honestly, in light of data breaches, etc, I get it. Many tools (most of the ones in this Ask HN) are cloud-based so this may limit your options.
I'm currently using OneNote to author and present ~300 pages of docs to ~3000 users. Being the SOLE author, this is fine. The style and structure are consistent, but I don't like it. OneNote doesn't support markdown (are you serious Microsoft?!? you don't have an f'ing markdown editor yet?), locks you up in a proprietary format, etc. etc.
Its also too "willy nilly". Its meant as more of a personal KM tool rather than a something for general consumption.
Where I lean:
* Static site generator under git version control
* Hook up with your local "Write the Docs" Meetup
* Check out the annual "Write the Docs" conference (coming up in a few weeks in Portland!)
* And start with YOUR OWN company knowledge.