There is an excellent episode of the PBS series Frontline about retirement planning that has a lot of good information about mutual and index funds. (Or at least I thought so. I am no expert.)
It’s also available on Amazon Prime Video. Just search for Frontline, season 31, episode 12
As for managed mutual funds, I always wonder, if they really can dependably beat the stock market, why do they need commissions on my money? Wouldn’t they just make money by beating the stock market?