DHCP and routing

[Jonathan Christison <jonbon_c blueyonder co uk>]

hello i was wondering if any one could help me, i have a single fedora
box with two network cards 
eth0 - connected to my isp wich DHCP's all my IP information and DNS
information this works fine......
and 
eth1 - Connected to my Hub and routes the isp to my other machines
including virius other network services like nfs and samba...
its all been thoght out except the major fault i havent a clue about
networking.
first of all i have given my eth1 a fixed ip of 192.168.0.1 and im
trying to run dhcp service it did nothing so i played with dhcpd.conf
file and it dosent work at all now it has the error: Line 1 : semicolon
expected.

and i just havent got a clue about routing im gussing i have to route my
isp ip to 192.168.0.0 but the porblem is that its a dhcp ip and will
change and i cant be botherd to change it every 5 seconds.

- Thanks for yore help ;) (i need it)