You want to stay with databases that are updated at least once a month. The markets for writers are vast and they change quickly. Always read the market listing carefully. Don't submit anything you have written that does not fully match the markets description and request, otherwise you will be wasting a lot of your time and theirs.
We are still experiencing an information explosion. This translates into a lot of opportunities to sell your work. You can find markets to sell what you have already written, or you can be proactive and look for markets that cater to topics you have knowledge in and enjoy. Then, after reviewing the markets in that niche, write something that matches what they are asking for.
There are a lot of successful writers who utilize both methods. Put some thought into what you want to accomplish with your writing. How often do you want to write? How much time do you have? Taking those two things into consideration and then matching them to your over all goals you will find that selling your writing becomes a whole lot easier.
Below, I have listed the top sites I found doing a recent search. I weeded out all the sites I found that do not update at least monthly.
My favorite place to find markets that are currently open is WritersMarket.com. They update their database at least once a month. They have tools you can use that other sites don't offer. You can save searches and sort out types of markets you are not interested in within a certain genre. WritersMarket.com is a paid website, however their monthly fee is very low and reasonable. Here are the different types of markets you will find there:
Greeting Cards and Gift Ideas
Online Consumer Publications
Online Trade Publications
Next, you have two good sources for writers guidelines. This is a good way to weed out potential markets. I do recommend obtaining current guidelines for the markets you find that fit your type of writing and interest. You can find current guidelines on most company websites, otherwise they will list an address where you can write for them. Be sure to include a SASE or you will not receive the guidelines.
Writers Write Guidelines Database
Writers Guidelines Database - Magazine
There are two Christian writing market websites. The first one, Christian Writers Market Guide, is an actual guide you can buy. They do not have an online database. The second is a Christian Poetry Market online database.
Christian Writers Market Guide
Christian Poetry Markets
I found two sites devoted to Poetry. The first one, Poetry Markets, takes you to their fiction section first. Next to the words 'Fiction' you will see to the right a link for Poetry. The second one allows you to submit your poetry through electronic submission.
click on poetry market tab on page
Poetry Publishers who accept electronic submissions
For those of you who are writing and/or living outside of the United States, here are two excellent online databases. The first one is for markets in the UK. The second is for Canadian and International markets.
Writers Markets for the UK
Markets for Canadian and International Markets
2014 Writer's Market Deluxe Edition (Writer's Market Online)