We are installing a ceiling fan/light combination in a new room. The fan requires 14/3 wire,
But the source is only 14/2.
1.) How do I connect the fan to the source?
2.) How do I terminate the fan at a switch?

I assume the 14-2 wiring you describe is white, black, and bare ground wire.

Will you be installing the switch to control the fan? The fan probably has a switch to control the lights, so all you need is switched power to the fan and using the fans instructions you make the light connection at the fan. If you want the lights controlled by a switch then you will need to run an additional 14-2 to the fan from that switch.

Hope this helps, but if in doubt call a certified electrician.

Where is the source? The ceiling or the switch? What you are after are two switchable circuits. Or, you can hardwire the fan/light directly with no switches and use wireless control.

A fan doesn't REQUIRE 14/3 unless you want to control the fan and light separately from the wall.

Right now is there a switch, and, if so, is there 14/2 running between the fan and switch? What type of switch setup do you need to accomplish?

Ceiling fan wiring - Ceiling Fans N More

The easiest way with best results is to use a RF switch with a transmitter,they sell them at Home Depot... $50... here is a link to the manufacturer web on the product.
Hampton Bay
Good luke