Ah stuff it, i'll type it up from memory.
Mac OSX up to 10.2.8
SETUP:
From wall socket -> Modem, run a phone cable, either through the filter/splitter, or straight from the wall.
All other phones in the house need the Filters attached to them.
Run the Grey CAT5 cable from the 530 to the MAC into your Built in Ethernet. This cable looks like a phone cable, but a bit larger, has clear ends.
CONFIG:
Once plugged in, and the modem is powered.
Click the Apple Menu -> System Prefs -> Network.
Select 'Built In Ethernet' from the 'Show' menu.
Click the PPPoE tab.
Fill in these fields, 'Bigpond' as the 'provider', your username in the Account name field, followed by @bigpond. (if e.g. shelly@bigpond), password in the password field.
Tick the 'Show PPP status in menu bar' box.
Click on the TCP/IP tab. In the 'Search Domain' box, put in nsw.bigpond.net.au
Click Apply now. Close the Network Config window.
Now, open Internet Connect either from the Dock/Status in the menu bar, or through the Mac HD in the Applications folder. Change the 'Configuration' box to 'Built in Ethernet' if need be. Click connect. If all goes well, Connect will change to Disconnect, and you're away.
See if that works.