InPhO: Use the taxonomy browser to find information on philosophical concepts at the Stanford Encyclopedia of Philosophy, Noesis, and Google Scholar web sites. (Indiana Philosophy Ontology Project).

PhilPapers: Online Research in Philosophy is a comprehensive directory of online philosophical articles and books by academic philosophers.

Since anyone can put anything on the web, you will need to evaluate what is high quality information and what is not. 

The following guides can assist you in evaluating web resources: