Taxes
Every investor should certainly have an overview of how and what they will tax in their portfolio.
Most of the time it is dividends, if you buy stocks in the US, dividends are taxed at 30%, but you can avoid double taxation by filling out form W-8BEN and once you fill out and meet the requirements, dividends will only be taxed at 15%.
You will also be taxed on, for example, shares if you do not meet the time test or your income for the year was more than 100,000k.
However, the reverse is also true, if you meet the time test (3 years) or your income from shares for the year was less than 100,000 kc, you do not have to pay tax.
Of course this is just the basics and there are other things and exceptions.
I would be interested to know what experience you have with taxation of shares and dividends and what your approach is.