Yup - what they said! There are lots of good avenues for finding markets - Duotrope is definitely a very useful site, and books that give listings for authors are great, but you always want to check websites etc. for the most up-to-date submission guidelines.

The only other thing I would add to what's been said is not to be nervous. It does take some nerve to start throwing things out there but, until you do, you won't know. ;) It's only through dipping a toe into different avenues that you learn what works where and for whom, so just take a few days to do the necessary research, then grab your most polished pieces and do it!

As holyschist says, short fiction doesn't pay much (though digital publishing has gone some way to redressing that balance, as short stories can be sold singly for Kindle etc., so you're no longer restricted solely to magazines and anthologies), but it is a great way to familiarise yourself with different places and markets.

Also, thanks for the links to those stories. I shall attempt to snatch some time to have a proper read this evening.