I think it can be done various ways, but we have a VoIP enabled ADSL Modem/Router, one little electronic device does all those things.Purchase an adaptor "splitter" box so that the phone can go off that and the other line goes to your wireless router for your home Internet usage.
Do you need to purchase a special phone to run off that splitter or can you plug your existing old school phone into it using the normal RJ45 phone jack.
It plugs into the phone line, it has 4 ports out for the ADSL/computer network and another RJ45 telephone jack for the VoIP that connects to a normal telephone (we connect it to a 3-way hands free setup).
Once it is setup and working correctly it's essentially the same as using your normal Telstra-type phone (I set it up for my parents and they are your age and had no problems with it).
A much bigger issue is running out of IP4 addresses, the issue is already here and already starting to be a problem, too many people/devices connecting to the interweb.I see a millenium bug thing approaching. Mobile numbers are all in the fomat 04xx xxx xxx