COM development

My entire knowledge on COM interaction and development has been attained from the articles I have downloaded from MSDN. These have been very informative however I am still not as comfortable as I would like to be with the subject, as in I still reference these articles all the time when I write COM stuff. I was wondering if there was the 'good book of COM' floating around out there that I have missed. I have seen Inside COM and Inside OLE referenced in the articles I have but I am unsure of how good they are. I really am looking for something for COM like Petzold's book is to Windows. Any suggestions will be greatly appreciated.

Inside COM is a good book if you pick it up second hand. It's a bit old but it will tell you how COM works under the hood without any reference to libraries like MFC and ATL - so, just what you are looking for! It will expain the basic ideas of seperating interface from implimentation, different types of COM server, type libs, marshalling, aggregation, dual interfaces & automation, multithreading..etc. All from scratch.

Inside OLE is a little more "weighty" with a bit more in-depth stuff, but not as good a starter as Inside COM

Both books are quite old now, so a search of ebay would be a good start