I'm on the Systers mailing list for women in tech, and sometimes I post there. It is especially valuable for technical women who don't otherwise get to talk with other technical women. I suggest people apply to Hacker School, I share info about jobs and internships, and I publicize calls for talks for conferences (and talk reviewers). It's a good place to share data about one's past experiences, e.g., "Last year I submitted three proposals and one was accepted."

And sometimes I say things like:

...it definitely sounds like your boss is, if I may, an anti-mentor. A rotnem.

Or, several years ago, on being one of the few women in an office and offering coffee to visitors:

At my office we have the same sort of coffee rule by default; the one developer who drinks it makes it. Our office manager (a woman) has naught to do with it except ordering coffee beans.

The other developers drink soda, and the rule there is that if you finish off the last Diet Coke in the fridge then you must move more Diet Cokes from the closet to the fridge. The office manager enfridgens a bit of each week's soda shipment as it arrives - that's all.

I agree with other Systers in saying that hospitality is great and dignified as long as everyone in your office treats it as an equal obligation. Whenever an interview candidate comes in to our office, s/he has about ten people saying, "can I get you some water?" over the day. It gets sitcom-funny.

Side note: Somehow "would you like some coffee?" can be made to sound more suggestive than "would you like some water?" "can I offer you a Diet Coke?" or "we have Emergen'C if you'd like it." However, there's really no good way to offer someone a serving of Yoo-Hoo. More research is required.

This was not actually the best message to send, because Systers is an international list but Yoo-Hoo is not an international drink, and thus follow-up messages were necessary to inform (and disgust) my correspondents. Ah well.