If you feel you need more help, check out this email program tutorial . Be careful what rights you are giving away. One-time electronic rights and the right to archive for a year or two seem standard. As a courtesy, you should not submit elsewhere until the story has been online for ninety days. You should always mention if the work has been previously published.
Word does get around.
Start researching the paying online magazines first. If you are still getting rejections after a dozen submissions, look for web sites that list new ezines. Low Bandwith and Newbie Writers Resource Page come to mind. You will have a better chance of a careful reading from a new magazine. Again, read the submission guidelines carefully.