I think linking and timestamp don't come with keyboard shortcuts, but you can add shortcuts for any command.

Keyboard shortcuts for OneNote:

• Alt-Shift-T inserts time
• Alt-Shift-D inserts date
• Alt-Shift-F inserts date+time
• Ctrl-K opens a link-creation dialog (or converts existing text into a link)
• Surrounding text in [[double brackets]] makes a wiki-style link, creating a new page with the enclosed title (or linking to an existing one) in the same section.

Also, any page or paragraph can be a link target, with its own onenote:// URL that can be launched from other programs that allow links to be embedded.

Yeah, if you happen to be on Windows and have OneNote 2010, it can be pretty sweet for this sort of thing.