I think you should choose a stock that trades on the NYSE and is also in the S & P 500. It should also trade at least 2 mil shs per day and be incrediblly financially stable, a very good credit rating is the best indicator. Finally it should have a stock price between 20-70 dollars. I think higher dollar stocks are better because they will tend to a have a larger average daily range, however lower dollar stocks may have tighter spreads making them easier to bailout of.
Hi I think this very much depends upon your trading strategy - what form of analysis/timeframe/risk preference you have. I follow a group of 12 NDX stocks incl qlgc, msft, ebay, vrts and whenever one of those stocks fits my trading criteria/strategy at a particular moment, I enter the market. I don't have any preferences from the 12 that I follow. I would stick to 8-12 stocks that you should really get a feel for rather than chop and change every day. Hope this helps