I am biased, but believe I am a decent source for this type of info! I will add a contradicting opinion - I say run far far away from Dentaltown and Dental Economics for business knowledge. The information is largely centered around sales, not written to provide useful information. In Dental Economics, there are tidbits of useful stuff for absolute beginners to the dental business realm, but take it with a grain of salt. Remember, to get the real information from those guys, you have to pay them. It's 75-90% sales driven, then every once in a while I read something awesome.
IMO, and this is just me, Dentaltown is worse depending on how you use it. Advice on forums is largely distributed by consultants - many of whom have no dental experience but plenty of business background. What I hate seeing on there is the consultants copying and pasting crap they already have laying around. Also, most of the consultants on there are very experienced - but with the caveat that many of them have not updated their practices in 10+ years. I do like Dentaltown when it's largely dentists having discussion, but sometimes its difficult to understand what they are talking about unless you've worked in the dental industry before.
Stay away from dental business books, the overwhelming majority of them are worse then the aforementioned resources. The best place to start, again in my opinion, is with your uni's classes, or youtube lectures from other universities. Focus on accounting, marketing, and management courses (economics is the study of the economy to understand interest rates, inflation, GDP; not useful for running a practice). Once you've learned the lingo of business, you will be able to apply it in a surprising number of ways to dental situations. Feel free to message me if you'd like to talk more.
Edit: glancing at this, its a bit harsh on those places. They aren't really terrible, but I still feel there are better ways to learn. I think the main thing to take away, and the reason why I dissent, is not because they suck, but you have to take it all with a grain of salt.
As a bonus, check out Dentalpreneur podcast by Dr. mark Costas, as well as Gary Takacs' podcast. Both not bad, I listen to them in the car and while I workout, but again they can be sales driven and useless at times, and amazing at others. Try the youtube courses from other universities before those to get an initial grasp. Hope this helped.