I've read to confusing reports.
One says that "Fruit production is greatest in full sun."
The other one says :
"The quickest way to let your tree die is to plant it in full sun here in the desert. This means you’ll need to plant your avocado tree on the east side of your property, preferably under a larger tree".

Which is it?

As is often the case with trying to get plants to grow in challenging climates, there are lots of exceptions, but it's a good idea to protect young avocados from extremes of sun, heat, and cold. I put a shade cloth over mine the first year when it started getting hot, and I covered them with a sheet during freezes during their first winter. It's better to err on the side of caution. Different varieties may need customized treatment--the in-ground Wilma wasn't fazed by hot weather this summer, but a 2-gallon plant grafted from the same tree really suffered, and had to be moved under the eaves. Leaves on the small Opal next to the big Wilma start shriveling when it gets really hot, so it needs temporary shade--but I'm hoping that will change as it gets bigger.

Thanks Ken.

Thanks, All, for your interest, comments & questions. And, thanks to TorontoJoe for instructions about posting photos even after reaching F4F's limit.

 
Here's a batch of Wilma guacamole I made for our Thanksgiving house guests, roughly following this recipe: http://www.foodnetwork.com/recipes/alton-brown/guacamole-recipe.html. It disappeared in a hurry! I also learned that on older fruit, where the skin has dried out and gotten somewhat wrinkly and tough, it was much easier to peel away from the flesh--which is why this batch doesn't show as many black bits as in the earlier shot.