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
