12-bit DAC Output to +/-10v Signal
a straightforward solution would be to use an opamp configured as a difference amplifier.

There's plenty of good material on the web about it. Here's one:
http://www.electronics-tutorials.ws/opamp/opamp_5.html

Let's say your DAC outputs 0V to 2.048V for code 0x000 to code 0xFFF (fairly common) and you want a swing of +/-10 Volts. So the gain you want is 20 Volts / 2.048V = 9.77

The circuit is below. So you just need R3 that many times bigger than R1.

The trick is to reference once side of the input to the "halfway point" of your DAC output range. So here, I'm referencing it to 1.024V. This way, the amplifier sees a difference (V_R2 - V_R1) on its inputs of -1.024V at code 0x000, and +1.024V at code 0xFFF. Then the opamp applies the gain of 9.77 to that difference and, voila, you get your -10V to +10V output swing.

For the voltage reference, just do a search on Mouser or Digikey. You will find a ton out there that put out nice "binary" values like 1.024V and 2.048V.

The difference amp configuration is super useful. I hope that helps, -Vince