Re: Selling short stories
As already noted, check the guidelines. Some mags say no simultaneous submissions, others just want you to have the courtesy to notify them if and when the story you submitted to them is no longer available because it just sold to someone else.
Try submitting your stories to the Magazine of Fantasy and Science Fiction. They rarely take more than two weeks to respond. You can wait two weeks, right?.
Also try some of the e-zines that take electronic submissions. They usually only take a couple of days to respond. This internet thingy is fast...