Well, here are some more links/information that will help:

Michael Peppler's homepage: the guy not only wrote several Sybase modules for Perl (and I thank him a lot for that!), but also has a webpage full of information on how to get everything up and running.
FreeTDS: you will need either this, or the Sybase libraries, if you're running Perl on *nix.

I have set up a Linux box with FreeTDS and Peppler's DBD::Sybase to talk to SQL Server 2000 on NT. Speed is not great, but it's serviceable.