The OP question was about minimum requisites. If you are interested in the definition of capitalism, one can be found in wikipedia also
http://en.wikipedia.org/wiki/CapitalismCapitalism is an economic system that is based on the private ownership of capital goods, or the means of production, and the creation of goods and services for profit.
Obviously, this can be discussed ad infinitum.
In a modern society:
1. It must be allowed to own things. You own yourself, your things and your work capatity. This includes capital goods, also sometimes called the means of production.
Lots of common rules reduce this. Some things you can not own, and some things are taxed, some things can not be imported and so on. In my country, a land owner does not own metals over a certain specific weight. If you can not give your wealth to your children when you die, do you really own it?
2. There must be freedom. You are free to sell things, buy things, give away things by your own choice.
Lots of common rules reduce this, like income tax, sales tax, tarrifs. You are forced out of work beacuse of a union. You can not cut someones hair unless you have a special costly education. You can not trade your work because of minimum wages.
3. Everybody is allowed to make his/hers life better, as defined by oneself. Consequently, some must be allowed to be more wealthy than others.
The ultimate progressive income tax, would reduce effective wages to the same level.
In sum, capitalism is everywhere (may be not in North Korea, I don't know for sure), but is also repressed everywhere to some degree.
The effect of capitalism is that everybody can achieve his maximum living standard (as defined by himself). In addition, the saving and investment, and division of labour will increase the productivity of labour, for the benefit of everybody.
There will be difference of wealth, but it is not clear that the current system of reduced capitalism better spreads the wealth. Subsidies of certain industries including banks creates large differences, and morre importantly it reduces the ability of the market to maximize utility.
Therefore, maximum capitalism, which is minimum regulations, minimum taxes, minimum government spending will create maximum wealth.
Using sound money will support capitalism, since it will take the inflation tax away from governments, take away the governments ability to manipulate the interest, and will make it easier to calculate profit and loss in business.