Just in case you're not following Julian's blog, I'd like to bring your attention to his new series on red-black trees. Red-black trees are great data structure, but are notoriously hard to code correctly as the algorithm is full of weird edge cases.
I've always been a follower of his 'algorithms and data structures' articles in The Delphi Magazine and I'm sure his new series will be presented at the equally high standard. He's using C#, VB and .NET but I'm sure the series will be interesting for us Delphi users, too. [And he already gave us RB tree implementation in the EZDSL library - thanks, Julian!]
Of course, if you own his DADS book, you can read all about RB trees there.