Almost 100 years old, but timeless. Follow the principles outlined in that book and what OrsoNero says above, and you'll be ahead of 90% of folks. For people in Soupie's situation, or once you've mastered all of the other stuff, it may be worth talking to a CPA, attorney, CFP, or other credentialed and registered investment advisor.

I have an affiliation with an investment advisory firm, but I don't want to talk my own book. If anyone is actually looking for that sort of thing, sure, DM me and I'll make an introduction, but most people can start at the OrsoNero level and have enough work to do there.

Disclaimer: this isn't investment or legal advice.