There are way too many sites on the net to just pick few of the best links and offer them as the definite source of truth and all things knowledgeable. yet I suspect personal blogs are much better sources of insight that many of the commercial and supplier websites. how do you find such places? I'd use a search engine, like google, and add blog as a keyword. Remember the information is not all of the same authority
There are however a few magazines/ezines like Digital Photography Now, that have External Links to good places, that will have probably have been selected because they are well informed, but in some sites they may just be those that pay to advertise.
The places I think are best are the many photo sharing forum poping up, and I am a memeber of Sharing Digital Photography Worldwide forum. Here you can interact with other photographers, and look through their forums, beacuse most of the things you are looking for are sure to have been worried about by someone else.
What I'm saying is it is hard to establish Aurthorative sites about didgital photography on the net, so beware. In any event you can expect to see a few more links from here to other bloggers, because they are also at the coal face, and a lot more up to date and therefore relevant