Philosophy Pages
Philosophy Pages: Logical Positivism
PhilosophyPages.com offers excellent information on logical positivism, including sections on verifiability and meaning, the logical structure of the world, and ethical emotivism.
Stanford University
Stanford Ency. Of Philosophy: Logical Construction
This site from the Stanford Encyclopedia of Philosophy discusses Bertrand Russell's notion of "logical construction" and its influence in the development of logical positivism. Mostly historical in orientation and is accessible to those...