[pop3] port addresses

[Mohammed R. Arjomandi]

Sorry if off-topic,

I want to know actual port numbers of communication programs.
I mean, 
        SMTP means TELNETing to port no 25,
        POP3 means TELNETing to port no 110,
        WWW means TELNETing to port no 80,
        FTP...
        ...
(and fill the others, if possible).
Is there any toutorial about port numbers and addresses?

Thanks,
Mohammed