Here is some of the best links for chess:
10! Computer Chess Club!!
10! Chessbase! Here you will find the top engines in the world, news about chess and many more....
10! Hundreds of free chess engines!
10! Winboard forum!
9! Arena forum!
9! UCI engines!
10! ARENA!
10! Computer Chess index!
10! Lokasoft! Here you will find top world class engines and more....
10! SSDF computer rating list!
10! Dann Corbit's FTP. You can find anything about chess! AMAZING!
And some of the best free programs:
9! Chessbase light! A great database program!
10! WINBOARD!
8! Old free chess programs!
5! Deep Basic chess! By Thomas McBurney.
9! Comet B-63! A strong free chess engine. (It needs Winboard or Arena).
10! Ruffian 1.01! One of the two strongest free engines. (It needs Winboard or Arena).
9! Crafty 19.17! A strong and leading free chess engine. (It needs Winboard or Arena).
9! Delfi 4.5! A strong, free, new chess engine. (It needs Winboard or Arena).
9! Smarthink 0.17! A strong free chess engine. (It needs Winboard or Arena).
8! Rebel Decade 3.0! A DOS free top program.
6! Mirage 2.07! An old but good chess engine. (DOS)
10! REBEL 12! One of the two strongest free engines. (DOS)