Who can tell me or provide me some good links?
Thanks.

fetchmail is very easy, either use fetchmailconf, or use the man pages. you'll often on need one line in the file

fetchmail -p pop3 -u whb pop3.sina.com.cn
then i enter my password,

it says:
47 messages for whb at pop3.sina.com.cn
reading messages fetchmail:SMTP connect to localhost failed.
fetchmail:cannot raise the listner;fallingback to$procmail -d %T.sh:-d:command not found.
fetchmail:MDA exited abnormally or returned nonzero status not flushed.
SIGPIPE thrown from an MDA or a stream socket error.
socket error while delivering to SMTP pop3.sina.com.cn
QUERY status =2(SOCKET)
terminated with signal 13

i'd guess you've not got a local mailserver running. Sendmail should ALWAYS be running on your system (if it got installed) as it's sendmail (or postfix, qmail etc...) that puts some mail in each /var/spool/mail folder. you get a socket error on smtp, so i'll bet it's that, and certainly not fetchmails fault.

Long time ago i removed it from my bootup list because it took too long time.
So should i add it into the list?
And why it says 'socket error'?

Unless fetchmail is compiled with sendmail as only mandatory MDA, it shouldn't be necessary to have the sendmail daemon running when you don't need it, and this behaviour is supported by your error message: it tells you, that after failing to find sendmail on your local SMTP port TCP/25, it decides to use procmail as local MDA (Mail Delivery Agent). Only here we see the shell (sh) return a failure for "-d", prolly because it aint quoted right. Now in your ~/.fetchmailrc there should be a line which states:
mda "/usr/bin/procmail -d %s"
I dont know why you use %T, I use %s, but the important part is the line should have the quotes as shown.