There's the old classics, like "Is Squidoo a Scam? An Honest Answer" which is a good introductory lens explaining how to get started on Squidoo and what you can earn.
And GreekGeeks Squidoo Tips: How To Get Your Lens Found is a useful lens explaining how to set up a good lens that deserves visits.
More recently, the Flapping Photo Gallery of DOOM is a fun way of pointing out just HOW ANNOYING the Photo Gallery module can be. I'd actually kept meaning to write a lens about this, because I use this module a lot, but I've procrastinated for months :D (And I have list of... well, dozens of things I'd like to write about)
And finally, Getting The Most Out of Squidoo's Traffic Stats explains how to interpret the dashboard, and what to do with that information.
Belatedly, that wretched person keeps writing more good lenses, thoroughly unbalancing my list of blessed lenses (eh, I'm behind anyway).
So more recently, I've blessed: