Delphi 7 developer’s guide
Arguably, Delphi 7 is the most popular version of Delphi that has ever been released. It is well regarded for it’s stability, quality, performance, and most especially it’s documentation.
The Delphi 7 developer’s guide [PDF] is still available freely (and legally) online at Embarcadero’s website.
Not only does it have great coverage of Delphi 7 and components, but covers some core Windows concepts (from a Pascal/Delphi perspective).