What should I use as a login and password while connecting to the bitcoin daemon I'm creating a pool, right now I'm trying to connect to bitcoin daemon, it responses with error "401", "HTTP Error 401 Unauthorized". 

What should I enter in "login" and "password" fields?
Locate your bitcoin.conf file (https://en.bitcoin.it/wiki/Running_Bitcoin#Bitcoin.conf_Configuration_File) and add these lines:

rpcuser = MyRpcUsername
rpcpassword = MyRpcPassword
server=1


These are the credentials you should be also using in your program.