Project Management Nuggets
Books: You'd be hard-pressed to find anything more comprehensive than the Project Management Bookstore online. It's a subsidiary of RMC Consulting, but if they don't carry the book, then it's not worth knowing about within the project realm. They periodically do author webinars (free) and provide other great resources for project managers.
Certification: I earned my certification back in the mid 90's before all of the great resources were available. From those I've talked with who've earned their certification (PMP) in the past decade, RMC Project Management provides the most comprehensive reviews available.
Blogs: Wow, this one is tough. But there are a few blogs that provide consistently excellent writings on project management, and have for some time. Among them, Raven's Brain (it's been a while since she's blogged, but even her old stuff rocks), Glen Alleman's Herding Cats, Kevin Brady, and Scott Berkun all provide pithy yet insightful ponderings on making your projects run more effectively.
General Sites: Top of the list are Gantthead.com and ModernAnalyst.com. Gantthead will appeal to the straight PM's among us, while Modern Analyst is geared toward the highly valued yet underappreciated Business Analysts. Looking for soft skills? The best bet in a project environment is OfficePolitics.com.
I hope these resources will serve you as well as they've served me.