Consult the list of participants at Jennifer's blog and click through to each blog to leave your comments!
This is such a fantastic idea. I am only sorry that I didn't learn of it sooner, or I would have joined. I also wish I had posted about it yesterday, when I first learned of it, because the participating blogs have varying deadlines and most of them are this weekend or sometime next week. Quickly now -- Go post at their blogs and support their noble causes before their deadlines pass!
I further challenge you to visit your local library this weekend, whether you regularly do so or haven't for a while, and ask if they accept donations. Donations need not be monetary - they may need volunteers and you can donate your time on a regular or random basis, and/or you may be able to donate books to the stacks or to their book sale!