You could also Google search for "Sprinkler Calculators.." Usually you can input your zip code, soil type, plant type, etc., and it will tell you how long you should be watering.

Does the planter have drain holes and does the plant medium have good drainage?

The planter does have drain holes, and when I'm watering by hand, it seems to go out the bottom fairly quickly. So I'm going to say yes, good drainage.

How big is "medium sized"

The best way is for you to get a moisture meter and measure the results of your watering. Set the run time for long enough to get the plants thoroughly wet, DEEPLY, and the days between watering to be enough to let the planter dry out a couple of inches.

I would recommend 1/2 gph emitters. Slower saturates the soil better and is easier to control in my experience. If you are watering with a can now how much water do you give it a day? If you give the pot a quart of water a day I would run a 1/2 gph emitter about 15 minutes twice a day. That is just a starting point you will undoubtedly have to adjust by digging down in the pot a bit and seeing how moist the soil is.

I got everything set up yesterday, I wanted to thank everyone for their input. I did some testing and for how long, and in the end went with the 1 gph emitter as the 1/2 just didn't seem to be enough. Over the next few days I'll work on making sure the timing is right.

Again, I really appreciate everyones help ^.^