William J. Bernstein wrote the Investor's Manifesto and over time it it has become one of the classic books on maing money from money.

Highlights:

Our homes are best viewed as a consumption item, not as an investment.

Successful investors need four abilities.
1. An interest in the process
2. More than a bit of math horsepower, far beyond simple arithmetic and algebra, or even the ability to manipulate a spreadsheet. Mastering the basics of investment theory requires an understanding of the laws of probability and a working knowledge of statistics.
3. A firm grasp of financial history, from the South Sea Bubble to the Great Depression.
4. The emotional discipline to execute their planned strategy faithfully, come hell, high water, or the apparent end of capitalism as we know it.

I expect no more than 10 percent of the population passes muster on each of the above counts. This suggests that as few as one person in ten thousand (10 percent to the fourth power) has the full skill set.

In the world of finance, the only black swans are the history that investors have not read.
Using historical returns to estimate future ones is an extremely dangerous exercise. It is even more dangerous to base financial planning decisions on the post-1925 database, a common zinger committed by many researchers and finance writers.
Stocks do relatively well during long periods of inflation, since companies can raise the prices of the goods and services they sell.
“Expected return,” one of the most important concepts in finance.
The single most reliable indicator of fraud is the promise of high return with low risk.
Important rule of finance: Always think in after-inflation, or “real” terms; this avoids having to correct later for the effect of long-term inflation. In the end, focusing on real returns streamlines thinking and helps investors tune out the noise they will hear about how inflation “corrodes wealth.”
The Gordon Equation: r = D/P + g which is : Return = Dividend Yield + Growth.
Always consider Pascal’s Wager: What happens to my portfolio - and to my future - if my assumptions are wrong?
“indexed” and “passively managed.” These are not quite the same. The former means that a fund buys all of the stocks in an index, such as the S&P 500, whose composition is determined by a committee within Standard & Poor’s Inc. Once each year, this committee replaces several of the 500 companies in the index; so too must any S&P 500 index fund.
Always remember the textbook definition of investment: the deferral of current consumption for future consumption. If you cannot defer current consumption, you will die poor, even if you are possessed of Warren-Buffett-like investment acumen.
Save as much as you can, and do not stop saving until you die.
Younger investors should own a higher portion of stocks because they have the ability to apply their regular savings to the markets at depressed prices. More precisely, young investors possess more “human capital” than financial capital; that is, their total future earnings dwarf their savings and investments.
REITs. How much? Probably no more than 10 percent of the equity allocation: 6 percent overall of a 60/40 portfolio, for example.
Commodities futures: Two things are wrong with this asset class. First, its future returns will likely be low - certainly much lower than they have been in the past; commodities are what I call an “asset class du jour,” on everyone’s financial lips. This is a real warning sign, since when everyone owns something, few buyers may be left to push up the price. Second, I just do not trust any of the commodities funds, or the companies offering them.
The more public visibility a company has, and the more well-known and entertaining its story, the lower its future returns are likely to be.
In recent years, the darlings of the story-telling crowd have been commodities funds and BRIC (Brazil, Russia, India, and China) country stocks, with disastrous results for those who read and listened to their claptrap.
A 25-year-old should be saving at least 10 percent of his or her salary, this means that a 45-year-old will need to save nearly half of his or her salary.
The commission and spread costs incurred by ETFs will quickly erode their minuscule expense advantage.
I do not trust most of the ETF providers to support these products over the very long term; all except Vanguard are publicly traded entities.

[From the Great Books  Series. Also see The Success Manual  - Encyclopedia of Advice, which contains summaries of 100+ Most useful books.]