All math.[institution].edu/~[professor]/ sites are great with, in of themselves, many links to the favorites of the page's professor.
It is like walking up to the professor at coffee and asking him about the tools he uses (resources) and how it applies to his research . A big cafeteria with the world's professors ressembled and willing to answer any questions... or at least those who keep their site up to date.
An example: http://www.math.ucla.edu/~tao/
Professor Tao's page is mostly blue (links).