I have been reading alot and we want to setup a secure ssh main login server that will handle logins for all our other servers. I have found some information but I need a really good rescource.
Can anyone help?
SSH is not going to "handle" logins for other servers. You need LDAP or NIS (LDAP preferrably) if you want to have centralized user login management. The users then ca use ssh to log into the servers.
Now, if what you are thinking is of a sever facing the net on one side, and your LAN on the other, then what you want to look at is VPN. Of course you can use "the poor man's VPN", a server that only allows ssh with key authentication for the side facing the net.