The Brain from top to bottom
This site devoted to the brain includes an incredible amount of information. You can browse the site by topic, level of explanation (beginner, intermediate, & advanced), level of organization (cellular, molecular, neurological, psychological, & social), module, or guided tour. The site already contains over 70 presentations on the brain (and it is still under development)! To give a sampling, the topics include: neurons, neural transmission, glial cells, memory, long-term potentiation, amnesia, how drug impact neurotransmitters, fear, anxiety, the evolution of the brain, the neuromuscular junction, and vision.