Download details: BizTalk Server 2004 Product Documentation

There is a new updated product documentation for BizTalk Server 2004 (7/23/2004).
Download details: BizTalk Server 2004 Product Documentation. There is a lot of new material about the Rule Engine, Engine Control Functions, Rule Action Side Effects etc.

BizTalk Server 2004 FAQ

A great resource for all those BizTalk 2004 server questions you have not found an answer for yet:

BizTalk Server 2004 FAQ - netologi.se

Windows XP SP2 - BizTalk 2004

The Service Pack 2 release for Microsoft XP has a lot of improvements on security settings. As a side-effect the regular install of the BizTalk 2004 Developers edition will fail at the Single Sign-On service.
It is all well documented by Microsoft, and easy to google if you know that the SP2 is responsible for the install failure, but just in case you did not make the link, read the article

The install failure is:

An unexpected error occurred while configuring the Single Sign-On server.
The service cannot be started, either because it is disabled or because it has no enabled devices associated with it.

Microsoft support article 841893 explains in detail how to resolve the issue by:

• Using Gpedit.msc to enforce the authentication of client calls

or

• Using Registry Editor to enforce the authentication of client calls