Stocks up/down short term

[testaaja]

I have really been into investing lately. What I find hard is to determine how a stock will move in a day or week. I know a stock, big industry (not all [img]/images/graemlins/grin.gif[/img])will probably go up in a month? year? but day I don't know.
So what I am asking is how do you do determine if a stock is going down or up in short term? Thanks.

Edit: ofcourse if there is more buyers than sellers the price will rise. What about news? Do they really affect that much?