Earlier this month, Chris Brogan, VP Strategy & Technology at CrossTech Media, shared 20 links to free e-books on social media. With Chris’ permission, I’ve reprinted his list below. Thanks Chris, and thanks to all the authors, for sharing this content with us.

1. The New Rules of Viral Marketing – David Meerman Scott
2. Marketing Apple – MarketingApple.com
3. Masters of Marketing – Startup Internet Marketing
4. Podcast Marketing eBook – Christopher S. Penn
5. Google Adwords Secrets – SEOBook
6. Get Viral Get Visitors – Stacie Mahoe
7. Marketing With Case Studies – Dynamic Copywriting
8. How to Write a Marketing Plan – Geisheker Group
9. SEO for WordPress blogs – Blizzard Internet
10. Social Web Analytics – Social Web Analytics
11. Geeks Guide to Promoting Yourself With Twitter – Geekpreneur
12. The Zen of Blogging – Hunter Nutall
13. What is Social Media – iCrossing
14. A Primer in Social Media – SmashLab
15. Effective Internet Presence – Effective Internet Presence
16. Introduction to Good Usability – Peter Pixel
17. Increasing the Response to Your Email Marketing Program – CRM Transformation
18. We Have a Website. Now What? – Craig Rentmeester
19. Blogs & Social Media – PRSA
20. The Podcast Customer Revealed – Edison Media Research

Photo credit: “30 Free e-Books to Learn Everything About Personal Finance,” originally uploaded to Flickr by  Mint Software