umask & dot forward

Gosh - got a few simple questions that I just can't seem to find the
answers to and I'm fairly certain that these are easy but I am a bit
pressed for time.

1. UMASK

I am trying to make certain that users save files in Samba that are
world readable. Samba has an option - force create mode...

i.e. - force create mode = 0775 would this make it so that owner &
group can read/write/execute and anyone can read/write? What's the
difference between a 3 digit umask (i.e. 022) and a 4 digit (0775)?

Is there a man page? - man bash & man umask are short on info.

2. Dot forward

If I want to auto forward a 'local user's mail' (and obviously I can do
things with sendmail aliases) I am under the assumption that all I need
to do is place a file in the users home directory. Is this file called
"procmail.rc" or is it called ".forward" and then, do I need to do
anything besides put the email address in this file that I want mail to
be forwarded to? Will this delete the local copy of that message or is
that retained?

Thanks

Craig