The "Vegan Sourcebook" by Joanne Steppaniak, "Becoming Vegan" by Brenda Davis,or "30 Day Vegan Challenge" by Colleen Patrick-Goudreau are wonderful. But for more detailed stuff online, check out the forums on www.ppk.com (Post Punk Kitchen). They have plenty of threads about all sorts of veganicity. It really helped me when I first became vegan. Colleen's podcast, titled "Vegetarian Food for Thought" is absolutely WONDERFUL and informative. I've listened to all of them. She also has a website called Compassionatecook.com. She just has such an eloquent, articulate, and compassionate way of presenting all kinds of vegan topics. She is really changing hearts and minds on a daily basis with the work she does.
As far as mouthwash goes, it CAN be vegan depending on the brand. I know JASON brand has mouthwash that is free of animal products and is cruelty free. Hope that helps, and drop me a line anytime with questions. I'll try to help you out.