There is no
steadfast rule for a writer of short stories. I mean, write one, ten,
or a hundred of them and then take stock in what you have. In a way,
I think it's probably easier to have one short story and make it a
really good one and then try your luck at publication. There are many
magazines that do not mind a simultaneous submission. So, take that
one story and submit it to 20 different publications and see what
happens. This is one tactic. The best outcome with this, of course,
is that each and everyone of the magazines except the last one reject
the story; this way you do not have to write each magazine to tell
them that your story was accepted by the first magazine.
Having ten short
stories in your arsenal, while a seemingly daunting task, may be
easier to balance. You can submit one story to one magazine (or two)
at a time, and get as much work out there as possible. After all,
this discussion has been about building a CV. Send out all of the
stories, and hope for the best. If you send out ten stories to twenty
magazines, you're sure to get one publication.