While there may be online places to check as well, assuming you're talking about pro markets, the canonical source for information is Writers' Market, published annually. It's probably not worth purchasing your own copy, because one trip to the library should give you all the useful information.
If you're talking about fanfic, well, I could make a suggestion for Pros, but I don't think you write that.
no subject
Date: 2010-12-29 04:46 am (UTC)If you're talking about fanfic, well, I could make a suggestion for Pros, but I don't think you write that.