There's plenty of info in BOL for this at "Strategies for Backing Up and
Restoring Transactional Replication"
http://msdn2.microsoft.com/en-us/library/aa237094(SQL.80).aspx.
Personally, what I tend to do is regularly script out replication, and if
the publisher/distributer server goes AWOL, I aim to reset it up from
scratch using a recent backup, apply my script (modified if the new server
name is different) then reinitialize.
Rgds,
Paul Ibison (www.replicationanswers.com)