I found a recipe for you, Joanna. Not having made it before, I wouldn't assume that the square pan variation would need a full hour of baking time as a loaf shape might. I'd probably check on it after about 45 minutes, allowing extra time if needed.
Hope it helps!

ZUCCHINI BREAD

3 cups all-purpose flour
1 1/2 cups sugar
1 cup walnuts, chopped
4 1/2 tsp. baking powder
1 tsp. salt
4 eggs
2/3 cup salad oil
2 cups grated zucchini
2 tsp. lemon peel, grated

Preheat oven to 350 degrees F.

In large bowl, mix flour, sugar, walnuts, baking powder, and salt together with a fork.

Beat eggs slightly with fork in medium bowl. Add oil, grated zucchini and grated lemon peel and mix with fork. Add liquid mixture to large bowl containing dry ingredients. Mix with fork (or fold with rubber spatula) just until moistened.

Pour into greased loaf pan (8 1/2 x 4 1/2 inches) or 2 square pans (8 x 8 inches).

Bake in 350 degrees F oven for 1 hour. Cool 10 minutes.

VARIATION:

PUMPKIN BREAD:
Use grated pumpkin in place of zucchini. Add 1 teaspoon cinnamon and 2/3 cup raisins.