Linking COM DB Objects

I have read Karl Moore's COM Course and in Part 2 he talks about utilising Class Collections.

Now, being new to COM, I would imagine this means if I had a table of Book titles, a Table of Authors and a Table to Cross reference Book to Author then this is what I need. (If it's not can someone point me in the right direction).

I have a COM object which connects and queries the Book Table. I want to look up the Author, do I add a query function or can I link the Objects somehow, by bringing back all Books, Cross Ref and Authors?

Thanks