John C. Bogle - The Little Book of Common Sense Investing
A long sales pitch for indexed funds, in a nutshell. Preferably the ones offered by Vanguard.
I did learn that indexed funds and ETFs are not the same. Need to investigate more. And that I should stay away from specialized index funds. Only focus on classic ones that track the whole market.
Whish the book covers differences between various indexes. Need to learn more about that as well.
There is no mention of REIT or gold and still no definitive answer on bonds (at least for non-US citizens).