Thought I'd collect my favorite e-mail marketing sites and blogs into one neat package. Some of the sites below require registration, but most are free to the world. I subscribe to all of them through RSS or e-mail, which is infinitely helpful in keeping up with them and not getting overwhelmed.
In addition to what's below, I tag a lot of Email Marketing stuff on Del.icio.us, which is always available here: http://del.icio.us/napdynmite/emailmarketing
Frequently updated and widely-referenced, probably th best single source of email marketing information.
http://www.marketingsherpa.com (sign up for the email marketing newsletter)
They offer a paid subscription and sell some nice studies, but the free content in the newsletter is fantastic. They also specialize in stats and benchmarking information found in few other places.
The deliverability kings offer up topics on a variety of "getting to the inbox" stuff and list management.
Campaign Monitor Blog
An e-mail marketing system vendor with a lot of insight from the reseller's perspective.
A top notch e-mail service provider's blog on a wide variety of topics from a smart bunch of practitioners.
http://www.marketingprofs.com (paid subscription and well worth it)
I unabashedly love MarketingProfs.com, not just for email, but a variety of resources, including a terrific email vendor matrix. Great content on email and much more.
Email Marketing Best Practices
I just discovered this gem and already feel pretty comfortable recommending it. Tamara Geilen covers everything from design to spam legislation. You could spend a lot of time here.
Targeted at email newsletters primarily, but a lot of great advice about best practices in email.
Email Experience Council
http://www.emailexperience.org/They're new and they're building up their cache quickly. Join and get involved. The site has some good resources as well as a mission.