This blog is an attempt to compile together such principles and rules, with links pointing to the more useful resources. To start with, here are a few rules that I can think of right now...
The Pareto principle, also known as the 80-20 Rule, says that 20% of your work will take 80 % of your time, and vice versa.
Wikipedia
Better Explained
Guy Kawasaki’s 10/20/30 rule of PowerPoint:
Guy Kawasaki suggests that a PowerPoint presentation should have no more than 10 slides, shouldn’t last longer than 20 minutes, and shouldn’t have any font smaller than size 30.
Guy Kawasaki
This rule, which became more famous (or infamous) as Jack Welch’s Differentation method, states that all the workforce in an organization can be divided into three categories: The top 20% (star performers, who must be awarded), the middle 70% (the core of company, who must be nurtured and monitored) and the bottom 10% (the non-performers, who must be moved out).
The Welch Way
This rule comes from David Allen’s Getting Things Done (popularly known as GTD). It says, a task that can be completed in 2 minutes should be done immediately.
Six degrees of separation:
Six degrees of separation is a wonderful idea which postulates that if you are one step away from each person you know, and two step away from each they know, then you are at most just six steps away from any other person in the world.... yes including the US President!Wikipedia
The rule of 72 is a quick (though approximate) method to determine how long an investment will take to double, given a fixed annual rate of interest. To find the time period, just divide 72 with the annual rate of return.
Investopedia
....
And while you are at it, also check out the following:
