I want to get acquainted with approaches made to solve P vs NP problem.
1) What is already achieved in solving the P vs NP problem?
2) What articles are most cited/famous in that field? Please, provide links for them.
3) How one can divide existing approaches to different classes?
Someone else posted this link in partial reply to another question recently. I think it answers 1 and 2, at least. http://www.win.tue.nl/~gwoegi/P-versus-NP.htm