If you'd like to contribute to charitable causes this season, but are a little overwhelmed by the sheer number of organizations out there, you might appreciate this post, where John Scalzi's readers provide their suggestions. (I had to add my own, of course.)
I enjoy the animated discussions in the blog's comments as much as I appreciate Scalzi's own commentary (on topics like poverty, privilege and respecting boundaries). I read several of Scalzi's sf novels before I discovered he was active in the blogosphere, and he wields one of the best banhammers I've encountered. While I may not agree with everyone who posts (or even with the blogger -- gasp!), they all have strong opinions and causes they passionately support, and I'd like to give to charities that inspire that.