I'm going to put a pergola in the middle of my yard as a shade feature. I would like to cover it in a good thick evergreen Ivy. What types do well here (Plano)?

It's not exactly an ivy, but it does climb. Carolina Jessamine is an evergreen with beautiful yellow flowers in the spring. It loves the sun.
For more ideas: http://www.dirtdoctor.com/radio.php?id=330

Where could I see some of this?

I also have small children & pets. I may need to look at a less toxic variety.

If your children seem to like to eat plants, yes, I would stay away from the Carolina Jessamine. I never did this myself, but I did eat bugs when I was little.
There is a picture in Howard Garrett's book "Plants of the Metroplex".
For a good online photo:
http://www.monrovia.com/plantinf.nsf/0/BB2186900A39DBEE8825684D007143CA

The list of poisonous plants is long. For a partial list:
http://www.inch.com/~dogs/poison.html and:
http://www.akca.org/library/poison.htm
To see non poisonous and poisonous lists:
http://www.flowerlinks.net/link_directory/poisonous_house_plant.html