It's not easy to read, it's certainly not written to entertain, but still one of the most important pieces of information on COM+ out there: U.S. Patent 6,422,620. PDF browser at espacenet , image and full-text version (you want to look at the text version first) at USPTO.
The patent explains how COM+ works internally -- how stuff gets activated, how policies provide extensibility points, how contexts are built and how context propagation works. The filing of this patent was a long while ago (Aug 17,1998), but the document was only published by the USPTO three months ago and although in XML times it may seem like anything 1998 must be outdated, this stuff describes quite well what's happening inside any copy of Win2K and up. Reminder: It's not a "how to" guide for hooking your own stuff into COM+, but allows you to understand what they've done -- reading this it is also a pretty complicated way to explain to oneself why WS-Coordination is such a relevant WS spec.
Related: US6473791, US6301601, US6134594, US6014666, US5958004, US5890161, US6425017
