To gather sources for this information, I started searching for reading guides related to feminism and activism. In some cases, I found relevant information from search engines, in others, I went to specific websites (like Feministing and Bluestockings) that I suspected would have relevant resources. The main problem I encountered was that it was far more common to list books, whereas it sounds like you're more interested in articles. If you do decide to read books but are unsure of where to get a particular book, you might try looking at World Cat, which shows you if a text is located in a library near you. For access to articles, if you don't have access to an academic database through a university, most public libraries have access to large academic databases. You can also start searching with google.scholar. Apologies if all this is old hat to you!
The Center for Women's and Gender studies at UT Austin has a really thorough reading list as a pdf.
On page 11 of the pdf, there's a section of materials for activists. This is mostly going to be books rather than articles, however.
Here's a discussion list about readings to assign to a course on activism. It's from 2006, but it might have some good materials for you.
On the Issues magazine put together a reading list of 2011 books related to feminism. Again, these are books, but many of them are edited volumes, so you could pick an essay or two from those that make sense for your group.
http://www.ontheissuesmagazine.com/2011fall/2011fall_books-of-note.php
The Atlantic put together a reading list of materials for feminist readings. This is going to be book-based, and might be more theoretical than you wanted:
http://www.theatlantic.com/sexes/archive/2013/02/a-reading-list-of-ones-own-10-essential-feminist-books/273337/
This is a reading list from an environmental organization, Up the River, about 75% of whom are women. Not explicitly feminist, but might still be of use:
http://www.uptheriverendeavors.org/materials/
This is one organization I don't actually know personally, so you might poke around the site a bit to make sure that they're an organization that makes sense for your group's goals.
Feministing is a great website that deals with contemporary feminist issues in a no-nonsense way. They have a tag (Weekly Feminist Reader) for keeping readers in the loop with news stories and events. I suspect this is more news-based/journalistic than your group is looking for, but just in case:
http://feministing.com/tag/weekly-feminist-reader/
Feminist Postcolonial Studies Reader
In addition to the excellent suggestions above, I recommend the collection of articles edited by Reina Lewis and Sara Mills, entitled Feminist Postcolonial Theory: A Reader (2003, Routledge). A copy may be in circulation at your library. I also recommend looking through publications by the Combahee River Collective (a Black radical organization working in the 70s and 80s), most of which have been published by Kitchen Table: Women of Color Press. And finally, if you are inclined at all toward any books, I recommend Chela Sandoval's Methodology of the Oppressed (2000, University of Minnesota Press), which may also be available from your library.