take it from a person who is working in financial industry. stay away. day trading is for professionals. if you have 20-30 mils, even then it's best to invest in several hedge funds, rater than do it yourself. you simply lack time, nerve, education and experience to compete. extremely bright ppl, w/ PhDs and what not make money on paper, but frequently lose in real market. they work 18-20 hours a day, and then on weekends. their job is to take your money from you. in real life if you open your door into the traffic, people will try to swerve and avoid hitting it; but on the market they will tear it off with your arm.
there are better/wiser ways to invest. invest in good mutual funds - good performers tend to stay that way for several months. find several of them, like one specialised in value stocks, one investing in bonds, one in midcap, one working w/ international securities. invest in real estate. keep some money in CDs. find couple of good companies and buy their stock because you think their idea is good. but buy it to keep it for several years. diversify, diversify, diversify! and watch it like a hawk! and to be honest with you, you *may be* will see the level of performance of S&P 500 after 5 years of sleepless nights and a lot of gray hair.
i know it's not what you wanted to hear, take it fwiw