I know it's sometimes popular to reflexively say that Delphi's help sucks. And it's not like Borland and Embarcadero haven't given us some cause, but the documentation really has gotten much better over the years. Of course, there are still issues; New features that aren't well documented (placeholder pages), help topics that are automatically migrated to a new version, but links aren't updated or are broken, etc.
If you've noticed a mistake or have a pet peeve with the help and you're so inclined, there's something you can do about it.
Embarcadero includes feedback links at the bottom of the each of their help and Docwiki pages. They've been around for a long time, but I'm told they aren't used very often. If you choose to let Embarcadero know where things have fallen through the cracks and/or what's important to you, then they will know where to concentrate their efforts. As the saying goes, the squeaky wheel gets the grease.
The Help Feedback link creates an email to the documentation team with the page name in the subject.
The Current Wiki Page link opens the associated Docwiki page for the current help topic.
Just like above, the email link starts an email to the documentation team.
The QP link launches Quality Portal and starts a QP report for the current Docwiki page.
Note: Docwiki has an interesting feature that lets you see documentation for a specific Delphi version by naming it in the URL. Leaving it blank takes you to the latest version available. The following links are for the XE2, Berlin and most recent (Sydney as of this post) versions of the same page, respectively.