To buy stock online one must register on the website and become a member and than the person should decide to buy the stocks with the help of broker or direct from the company.
Before purchasing stocks online one must make the survey if the stocks he is going to buy of a company and than only should make a further move of buying the stocks of the company.
One should make a decision of how much can he spend money on the purchase of stocks so that the financial problem does not arise.
One must also be aware of the trading rules so that he does not feel cheated if the person loses his money in any case.
One must make the list of companies he want to invest in taking stocks.
One must select the mode of getting a stock i.e either direct from the company or with the help of a broker or by opening an account in the bank and deposit the funds in the account.
The person must also have the knowledge of when to buy and sell the stocks so that he earns the profit of the stock he has purchased.
One must also have the knowledge of the companies that are into this profession and are accurate about their views so that the investor gets the exact and the perfect guidance in investing his funds and one does not make a loss.

To buy stock online, the first thing you need to do is find a good legitimate online broker, and sign up for an account with them. The next step is to consider and analyze the stocks offered by the broker, and make your decision on what shares you would like to buy. Much as this is not all there is to stock trading, it's a good starting point. However, it's a good thing to educate yourself as much as yo can, in order to avoid common pitfalls.