We looked around sitemaps, different Apple domains, and searched for things most people probably wouldn’t search for. Some dedicated Apple fans might know about some of these webpages, but I have a feeling a lot of fans won’t know about most.
Disclaimer: It’s probably best to not sign in to any of these sites in case Apple were to think you’re attempting to compromise any of their systems, or to place any orders on any government or educational stores as doing so could be breaking the Terms of Service or other policies.
You might know about these…
Workflow: https://www.workflow.is
“Remembering Steve Jobs” page: https://www.apple.com/stevejobs/
Downloads: https://support.apple.com/downloads
Apple Sales Web: https://asw.apple.com/home

But did you know about these?
Apple Training Courses: https://training.apple.com/us/en/courses
Claris: https://www.claris.com
Apple Training and Certification Guide: https://www.apple.com/au/education/docs/Apple-TrainingCertificationCatalogWeb.pdf
Apple RSS feeds: https://www.apple.com/rss/
Apple User Groups: http://appleusergroupresources.com/online-apple-user-groups/
Apple Certifications System: https://certifications.apple.com
Global Service Exchange: http://gsx.apple.com/
AppleCare OS Support: https://www.apple.com/support/professional/it-departments/
Apple Technical Learning Administration System (ATLAS): https://atlaslms.apple.com
Volume Purchase Program: http://volume.itunes.apple.com/us?l=en
Apple Gift Cards from $10, and in bulk on Apple Store for Government: https://ecommerce.apple.com/asb2b/catalog/browse.do?key=0/FB04B0B0099F1EDB858F4268B299D7F4/FB04B0B0099F1EDB858F53BDC327D7F4
Most Apple products, even those discontinued for many years, have their own technical specifications document. For example, the 2017 12-inch Retina MacBook and the iPhone XS.
