A number of these sites change regularly, so plan to visit them more than once. Philip Greenspun's Photo. This is a treasure trove of photographic resources. There are many original technical articles, as opposed to just lists of things.
Good photo essays too.
Mythago A gallery of the works of fine art photographers, predominantly involving figure studies. This gallery draws forth images from the edges of the imagination. Filled with strangeness and delight, these images change into new ones, constantly fresh with emotion and ideas. There are many links to works of other photographers having a similar emphasis. The subject matter is outstanding scenic and wilderness areas in California and Oregon.