Cancer.Net is a patient information directory published by the American Society of Clinical Oncology.  As they state on the homepage all the information on this site is ‘oncologist approved’ so you won’t find much here about integrative or alternative treatments but you will find reliable basic medical information as well as psychological, and practical advice on dealing with all types of cancer from diagnosis through survivorship.

I think this well organized directory would be a good starting place if you or someone you care about has recently been diagnosed and you are looking for some facts.  I especially like the section: Caring for the Whole Patient and Questions to ask your Doctor

You can find good basic medical information about all types of cancer at this website, including rare cancers and cancer related conditions.  It also provides printable guides and information in Spanish.