Local photography club. There is a 70 year old Marine Veteran that has taken me under his wing. I just joined and we have went out shooting already. Guess us Marines do stick together. He uses a Nikon D3S.
I like Nikonians and Nikonites along with Cambridge and this forum. Probably the most useful resource has been that little screen on the back of my Nikon. My highly technical technique would be best described as "Shoot and fiddle - then shoot again!"
As I have noted several times on this forum, my photographic expectations are probably a dozen notches or so beneath some folks on this forum. I shoot as a hobby, not as a profession. I don't sell my photos and really only print at moderate sizes (8x10 would be a large print for me). And I typically print my own stuff on my own little Canon inkjet printer. I have a few poster sized photos I have had framed but, honestly, they were mostly taken with a $10 Bell and Howell point and shoot film camera about thirty years ago or my first Canon Rebel film camera with a rather **** lens. The shot itself is why they were chosen to be framed not because they exhibit any great photographic technical merits.
That puts me on a learning curve that started long before the internet and even mostly before "how to" books populated the libraries. Therefore, I would have to say that while I have read and studied the "how to" guides over the years, the best learning tools I have used have been; 1) the camera's owner's manual and, 2) experience.
The move to digital photography has made the former more complicated and the latter much less expensive.
Otherwise, my personality type is a "visual personality" as primary. I've dabbled in hobby based art since I was a child so I was well aware of rules of composition and so forth before I ever picked up a camera. I'm of the opinion your personality type will be your guiding light when you begin to learn anything. If you are not a visually oriented personality and you want to engage in photography at any level, then you must find your type and discover how it can be used to your advantage - the old idea we all learn in our own way and at our own pace. Rules are there only for those who do not fit into the personality type required to master said rules.
If you are not a visually oriented type, then composition will typically be a bit of a struggle for you. If you are a visual type, you may become lost in the technical buttons and knobs aspect of a digital camera. You'll see the image in your head and you'll need to learn how to make that appear in your final image. Digital has complicated that IMO since a shot is now only a series of on's and offs, bits and bytes, filters and distortions inside your camera and computer until you do something else with it.
My visual type of personality shows in my general dislike for post production. The film based concept of getting the shot in the camera is only partially true for a digital image. My computer skills are still hovering around 1999 levels so I struggle with post production in many cases and could certainly turn out better quality images if I stepped up my game there. Just this last weekend I was shown how to attach images to a text message - and I hate text messages.
I still see many forum members here and on other forums I visit when they come up in a search engine talking as if the camera and its immediate gear (lenses, filters, tripods, etc) is all that matters. The compartmentalization of today's photographic experience is something I doubt I'll ever become accustomed to. Look here for rules on photography and scroll down to another forum for what to do afterwards.
Therefore, my "most helpful photographic resource" currently comes down to patience and, sadly, more cash than I reasonably have to put into a hobby. The days of a $10 camera are about as distant as the time when you could buy a new car for $3k.