Congrats! I too have recently become the proud parent of a few flat circles, and I do mean proud. The first few weeks I picked up crocheting my husband would say "ohhh, crocheting another tube?".
BUT today he took me to ACMoore because he wanted to look at the yarn he'd like me to use for his hat. hehe. It will be a while before I attempt that but at least he thinks I'll be able to eventually. I'm a big fan of the book and I don't even have it yet. It's definitely on my list!