You will need 2 shallow dishes or bowls.  A pie pan works great. 

Pour 3/4 cup of milk into one pan. 

In the 2nd pan mix equal parts flour and cornmeal, then add salt, pepper, and garlic powder.  Dip sliced Zucchini in flour, then milk, then flour again.  If you want to have crispy chunks on your zucchini, pour a little bit of the milk into the flour mixture to produce small chunks.  Use a fork to break down larger clumps.

Place coated zucchini in hot oil over med/high heat and fry until golden brown. You may need to do it in batches. Do not crowd the zucchini.

Place cooked zucchini on a plate covered in paper towels to help pull some of the oil from the zucchini. Sprinkle with more salt, if desired.