There is a commonly quoted statistic that only about 5 percent of day traders succeed. This is a good approximation. Most people who try day trading will not succeed, yet most of them do not practice everyday for six months to a year either. Time investment and quality practice increase a day traders chances of being in the 5 percent that are successful.
In addition to knowledge of basic trading procedures, day traders need to keep up on the latest stock market news and events that affect stocks—the Fed's interest rate plans, the economic outlook, etc. So do your homework. Make a wish list of stocks you'd like to trade and keep yourself informed about the selected companies and general markets. Scan business news and visit reliable financial websites.