We use Material for MkDocs to build our guide.
Once setup - simply run mkdocs serve locally for a live preview. Another option is running mkdocs serve -a localhost:8080 in case you want to specify a different port, by default, the project will run at the port 8000.
We are using the mkdocs-print-site-plugin plugin to add a print page that combines all the docs, allowing for easy export to PDF and standalone HTML.