I think the directions on the http://www.freetds.org website are pretty good.

I've gotten it working with SQL Server 2000 without too many problems.

I used the

    try server login = yes
    try domain login = no
[download]

options. I'm not sure domain login would work. You have to add a section for your server to the freetds.conf file; the docs on that are pretty clear.

One thing to note is that if tables don't belong to the sa user, you have to reference them as user.table, or you get VERY uninformative error messages.

Apart from that, DBD::Sybase works just fine.
--
Mike