I'm looking into this VoIP stuff and I'm awefully confused. There must be a million options. When reading about any given solution, how do I know if it'll allow me to use a regular handset rather than require a computer program to make and receive calls?
I don't think you actually need a "router" for this.
There are devices called "ATA" (Analog Telephone Adapter). Technically- they enable every "regular" analog phone to be used with VOIP services.
For example, Vonage uses "Phone Adapter"s, which you can use with your home router.
VOIP routers are just Routers with embedded ATAs.
Just make sure that the VOIP protocol is supported by the ATA, and your regular handset will work with your VOIP provider.
If you want to use a regular handset without "computer program" you'll need a VoIP or SIP router.
With a SIP router you can use your regular handset to make VOIP calls, nobody has to sit at a computer, in fact the computer doesn't even has to be turned on.