Constant Contact - E-Marketing An economical provider of e-newsletters, e-letters and online surveys - I've used their statistical tracking and find them good for small businesses.
Online Training for Software & Web Lynda.com has tutorials on everything from Adobe Illustrator to SEO tactics - I like the way they break down the courses into manageable segments. Tips on Writing for the Web
Jakob Nielsen provides excellent info, backed up by data on web reader habits.