IMO, No questions are dumb when a person is trying to learn.
Setting the dish on a temporary tripod has lots of advantages. You can move the dish around and see what satellites are available at a given location. In a way, this is extra work but it may save you from digging a hole and planting a dish pole that you need to move.
For me, a good motor pole will be about 2.5 inches in outside diameter. It will be black steel pipe with a schedule 40 wall thickness. I expect my ku motor poles to hold up to 50 pounds of weight.
Motor poles can vary in length. Here in Atlanta and the surrounding area, we have a clay type of soil so digging down real deep and using a lot of concrete is not really necessary. 2.5 to 3 Feet deep is about as far as I care to dig for a ku motor pole.
The length of the pole is decided by the area where the dish will be installed. In almost all installations, about half of your dish will be above the top of the pole. this means that you could probably get a 5 foot piece of pipe and put 2 feet of it in the ground, leaving 3 feet to run your 3 foot dish. This would be cutting it close but it would probably work with a ku motor.
For my installations, I like to get a pipe that is between 8 and 9 feet long. This length gives me plenty of pipe to stick in the ground and the completed installation leaves me with 5-6 feet of pipe to work with. I do not like to go any higher than 6 feet because the pole is easier to move on its own, plus you may need a ladder to make adjustments.
In December of 2007, I wrote an article on installing a motor pole. Some of the things I did are overkill but I have not had any problems with that pole. The motor pole .pdf file can be found in the link.
http://www.legitfta.com/forum/showthread.php?p=161#post161