One could read this as a free-standing book, but i'd suggest starting with the first one (Museum Mile). It gives a better introduction to the characters, and a better explanation of Eddie's photographic memory. But if you want to start here, go ahead.
This series still exemplifies the values of thinking and teamwork over brute force and antisocial behavior. Even the unfortunate vomiting episode late in the story carries a lesson about thinking before you act. Yes, there are still plenty of poor decisions, plenty of incidents of Eddie lying to his parents and disobeying police and other authority figures, the sorts of behavior a parent would rather their child not idolize. However, for the most part the adults aren't evil or incompetent, but rather busy with Adult Things or bound by Adult Responsibilities and unable to humor a kid's insight. It's certainly vastly better than many other kids' books out there, which make adults seem at best dismissive, and usually far worse.