Publications (both paper and net)
Delphi3000 - excellent article collectionThe Unofficial Newsletter of Delphi Users
Informant Communications Group (Including Delphi Informant)
DelphiZine - the excellent Delphi Informant site, lots of very good articles
The Coriolis Group
Pinnacle Publishing - several publications, including Delphi Developer
Delphi Tools
Astatech The Best N-Tier Components. The easy way to access your DBs through the net.ElevateSoft, home of DBISAM, the best embedded db engine for Delphi.
TMS Software Great (and cheap!) component collection, including a very nice grid with lots of features.
Developer Express Great components, including the QuantumGrid, easily the best grid available for Delphi. A bit pricey, though.
EFD systems Several tools, in particular, Hyperstring, a great string manipulation library.
Delphi Sites
efg's Computer Lab filled with articles and links, specially great in anything related to graphics.VCL-Components Component repository.
Delphi Pages Component repository, also some articles/reviews/etc.
Delphi Super Page (USA mirror) Component/tools repository.
XML
Books on XML and XSLTArticles/Tutorials
WebTools - XML toolbox Several interesting articles
The Basics of Parsing XML in Delphi 5 - by Charles Calvert
Article on using XML with SAX on Delphi.
Article on Creating XML from a dataset.
Several Examples on XML and XSL on Delphi
How to Redistribute the Microsoft XML Parser
Parsers
Native XML parser for Delphi - Open Source
Open XML Native XML parser for Delphi - Open Source - Dom Level 2
Native XML parser for Delphi - Commercial
MSDN Online XML Developer Center
CD-R Libraries
CD-R WritingCDWriterXA - Burn Audio CDs from .mp3 and .wav files to your CDR/W - US$229
NuCDR - Write data and audio tracks to your CDR/W - US$299
CDRipperX - Digitally Extract CD Audio - US$169
CD-DA Extractor
Other resources
Wotsit's File Format Collection If you need information on a file format, that is the best place to go.Delphi / InterBase WebLog Very Interesting collection of links and news for Delphi and Interbase developers. Updated very frequently.
Artificial Intelligence in Games Easily the best page on the field I've ever seen. If you're interested in the subject, a must see.