XY Graph for Inverse Function?

I need to graph $\displaystyle y=x^2+4$.

I understand subbing in values for X to get Y. The graph is a positive (opens upwards) parabola.

The inverse would be. $\displaystyle y=\pm \sqrt {x-4}$

As for graphing, I usually use x values of -3,-2,-1,0,1,2,3.

Do I substitute those values into the inverse equation the same I would the regular function?

If I sub the value of 0 in for X, then X-4 = -4. Then nothing is the square of -4.

How do I calculate to find Y properly, when working with an inverse equation?