Maybe you should reword your question to be "What are some good instructional resources for learning logo design?" Because simply looking at lots of well-designed professional logos and analyzing them yourself is arguably one of the best ways to become a good logo designer.
You can't really be instructed into becoming a good logo designer. Most of the nuances of great logo design can't be taught or even put into words. It's not like there's a straight-forward formula or checklist for creating awesome logos. Sure, there's an academic side to design, but that's only a small component of becoming a good designer (just look at all the design school graduates who suck at creating actual designs).
So you can't just pick up a textbook or go to a website and expect to be "taught" how to be a really good designer. Most of what's required to become a good logo designer is developed through years of training/practice. That requires you to be more pro-active and teach yourself.
Specifically, you need to cultivate a strong aesthetic eye and develop your creative instincts. There's no textbook or tutorial that can teach you those things. It just takes lots of dedication and hard work. And there's no better resource for these things than:
- logo galleries/showcases - which allow you to "feed your mind" with good logo designs; the more you immerse yourself in good designs, the sharper your aesthetic eye becomes, and the more your own designs will improve; aside from their high concentrations of good logo designs, galleries also help you identify current design trends—which are ever-changing and another reason to constantly keep your eye out for strong designs;
- practice design briefs - the best way to improve at anything is still good old-fashioned practice; an even better way of practicing than downloading practice design briefs is to enter into design contests (plus, you can win stuff like an iPad, iPhone, Wacom tablet, or even cash);
- design case studies - case studies are the counterpart to design briefs; they show you how other successful designers approach specific design problems; again, it's not instructional, but they walk you through the thinking process of other designers and help you improve your own creative process;
- design communities - design communities like Behance.net, deviantArt, etc. allow you to post your work and get critique from your peers; depending on the quality of the community, this can be an invaluable learning resource;
There are instructional resources out there, but I think you'll find that most of them deal with the "fundamentals" or theory of design. Sites like Logo Design Love are certainly useful, but most of their content are just articles like "Top X logos for 2010", case studies, workflow tips, or general advice on the creative process.
Edit:
I I will however recommend the Logo Design Workbook by Adams Morioka. It's the closest thing to an instructional book on advanced logo design that I've come across. But a lot of it is just case studies, design theory basics, etc. However, it teaches you a lot about the business side of logo design as well. And it's just an overall good read.
