Regarding philosophy:
Do you have any specific research interests?
Generally speaking, the Stanford Encyclopedia is the best online source of information about philosophy. I would recommend reading the following article:
http://plato.stanford.edu/entries/logical-empiricism/
Here are the titles of what are considered to be the most influential works of the 20th century:
http://commonsenseatheism.com/wp-content/uploads/2011/02/Lackey-What-are-the-modern-classics.pdf
Regarding philosophy:
Do you have any specific research interests?
Generally speaking, the Stanford Encyclopedia is the best online source of information about philosophy. I would recommend reading the following article:
http://plato.stanford.edu/entries/logical-empiricism/
Here are the titles of what are considered to be the most influential works of the 20th century:
http://commonsenseatheism.com/wp-content/uploads/2011/02/Lackey-What-are-the-modern-classics.pdf