If you are just starting out, I'd keep it simple. If you add 12 grains to an IPA, you really aren't going to know if you like any of them. If you start with a nice, clean recipe, you can add a new element each time and really see what YOU like in your IPA.
eg Extract + 1/2 lb crystal. (with the crystal in the 10-60 range depending on the color you prefer)
Once you've tried that, you'll have a base to compare to. If you want to lighten it up, you can add corn or corn sugar. If you want a little more "mouth feel", you can add some carapils. If you want a little more sweetness/carmel, you can add some more crystal. If you want a little more bready, malty taste, add some of that caramunich.