rather than going with what can be a bit of a hassle sometimes ( the ethernet option ) , I would suggest trying the Intel Anypoint 3240 USB modem . They have got more info here click here?
You don't use the DSL filter with ethernet , but yeah , if you do choose to go that road , connect it with your NIC card - again check the correct PPo? settings with that of Freeserve's .
It won't dial up automatically on restarting your PC but this can be sorted out by adding it to your startup menu so that it does . You usually have to contact the router/ethernet modem by going through IE ( typing in the IP Address of the modem/router in the address bar ) and then accessing the connection from there .
D-Link are well respected hardware providers too . Hope this helps