There's really no good substitute for hands on experience and direct observation. Often times this is first gained through unpaid internships or just plain volunteering to help out on a friend's shoot as often as the chance presents itself. In both cases you will have great opportunities to see how lights are rigged, mics concealed, camera moves blocked and so on. While you can learn from trial and error (which you invariably will) and you may pick up a few ideas from others also just starting out, it won't be necessarily a fast way to get ahead.
Speaking of which: [Chris Wood]"
Basically, I'd like to find some good forums for amateur / independent / student filmmakers where we can all get together and discuss and offer advice on filmmaking."
In many respects you've already found a great resource here in the COW. While there are many newbies posting here, and many, many more lurking, there is also a huge number of seasoned pros. Ask questions in the Lighting Design and Cinematography forums in particular and the chances are fairly high that your questions will be addressed by people working in the highest levels of the film and television industries.
Also, don't forget that the majority of the COW forums have archives which go back several years. There is a LOT of information there as well in the hundreds (or is it thousands) of tutorials.
And a small plug for the forum I helped start, don't hesitate to visit the COW's "Business & Marketing" forum when you're ready for advice on pricing and selling your services as well as dozens of other topics related to making a living in this business.