In no particular order, and based on highly unscientific criteria, here are my favorite online resources for high-tech direct marketers. Know of another great site or e-newsletter not listed here? Send me an e-mail and I'll consider it for a future edition.

Marketing Sherpa
http://www.marketingsherpa.com/
Anne Holland and crew at Marketing Sherpa consistently publish some of the most interesting, detailed case studies, reports, and other highly readable information for marketing professionals. Their B2B and Great Ideas newsletters are especially useful.

SoftwareCEO
http://www.softwareceo.com/
Bruce Hadley has created a very lively discussion forum for software executives, with topics ranging from Lead Generation to HR to Legal. If you have a question, chances are that someone's already asked it here. (Note: I co-moderate the "Marketing & PR" forum.)

Marketing Profs
http://www.marketingprofs.com/
One of the best marketing-oriented newsletters around. Reliance on outside contributors make some of the articles more self-serving than say, Marketing Sherpa, but the topics are current, the authors know what they're talking about, and there's at least one good idea in every issue.

White Paper Source
http://www.whitepapersource.com/
A new and growing discussion forum on a hot marketing topic: content syndication. Frequented by both advertisers and publishers, it's a good place to go if you're seeking a freelance writer, or looking to generate more leads from your white papers. (Note: I moderate the "Lead Generation" and "Advertising & Syndication" forums.)

BtoB E-mail Marketer Insight (Newsletter)
http://www.btobonline.com/register.cms
Most e-newsletters from major marketing publishers are little more than re-packaged press releases, but this bi-weekly newsletter seems to rise above the norm. Their "Ask the Expert" feature is well-written and informative.

Web Digest for Marketers
http://www.wdfm.com/
A great Web site (and weekly email newsletter) with reviews of marketing-oriented Web sites covering everything from direct marketing to search engine optimization.

Free E-Mail Spam Checker
http://www.enetplace.com/spam-checker.html
If you don't otherwise have the software to do the task in-house, this is an effective (and free!) way to view your upcoming e-mail or e-newsletter from the perspective of a spam filter. Generates a report with suggested corrections on how to stay out of junk folders.

Marketing Terms.com
http://www.marketingterms.com/
Just what is a blog anyway? What's the difference between CPA and CPC? When your boss asks whether you should be starting an affiliate program, just what exactly is he/she asking for? This is a great site for pretending to know more than you really do.

PaperSpecs.com
http://www.paperspecs.com/
Those of us who have been around the direct marketing industry for a while remember bookcases overflowing with swatchbooks of paper samples. If direct mail is part of your marketing mix, here's a convenient way to investigate paper options from the comfort of your desk ($14.95/ month membership required).

Connect Direct
http://www.connectdirect.com/resources.html
No bias here, naturally. But where else can you find more than 100 tips on high-tech direct marketing, plus white papers, articles and Webinars on lead generation, e-mail marketing, copywriting and more?