ATRP2iz has a good list, watch Index, Currencies, Bonds, Oil, and Gold, those are the big ones that will move the market, i only have them on a quick glance, to determine long/short bias, like if the markets cratering you dont wanna be buying breakouts, its just an overall view, then i make a short list of 9 stocks every day, and of those 9, I have 2 ideas that im going to take right off the open if the stock does what i think its going to do. Most days i dont stray very far from the 2 best ideas, might trade 1 or 2 new ideas that pop up on the scan but mostly, i just keep adding in too my two if its going my way or keep trading it on the same side i thought it was going to go before market.
The 9 charts i keep on other screen is just so i can glance over and see if anything is really obvious when the main 2 dont pan out. (only reason its 9 is cause 9 takes up 1 screen) but dont get yourself too hung up on a million stocks otherwise your going to feel like you missed everything.
And your going to get confused, the way i see some newbs trade its a goddamn miracle they are able to do anything with how much their paying attention too. Ive seen guys with 4 screens full of charts and they dont short list it and they just think they are going to look over and buy or sell what looks good, it rarely works.