I've been doing fresh tomatoes to pizza sauce for over 10 years and my methods have changed. I used to blanch and peel them, but no more because it's too time consuming and I typically have to process 50 pounds or more over a period of 10 weeks or so during the harvest season.
Here's how I do it now...
* Wash tomatoes under tap water, cut off tops, cut out any rotten pieces or white pulp and then cut them into halves or quarters which allows me to poke my fingers into the cavities to get the seeds out and drain the watery stuff.
* Next, place the chunks of tomato in a standard blender and pulse it a few times just to break them up.
* Pass them through a hand cranked food mill using the smallest screen (1/16" holes) which removes the seeds and skins. http://www.amazon.com/MIU-France-Stainless-Steel-Food/dp/B0000DZDFN/?tag=pizzamaking-20
* I then put the liquefied tomatoes in a "fat separator" pitcher and let it sit in the refrigerator for 6 to 24 hours. The water sinks to the bottom and I'm able to pour it off.http://www.bedbathandbeyond.com/store/product/oxo-good-grips-reg-4-cup-fat-separator/1013355266
This leaves a you with a thin sauce that you can thicken further by cooking down, or straining further through a cheese cloth, or just adding tomato paste. I'm still experimenting with all 3 of these methods.
After all the above, use your preferred method of adding spices, and cooking or not cooking the pizza sauce.
Here's my current pizza sauce recipe using the liquefied tomatoes...
16.0 ounces Liquefied Tomatoes
0.25 ts Salt
1.00 ts White vinegar
1.00 ts Olive oil - Bertoli classico
1.00 ts White sugar
0.13 ts Hot Pepper, fine ground
Heat over low flame to about 140 deg F.
Sometimes I cook it down (20 to 40 mins) to thicken,
or I'll just add some tomato paste cooking just long
enough to blend in the paste.
I freeze it for use up to 1 year later, at which time you can add more seasonings or just use it as is.
Like I said, I've done the blanching thing and I've done it this quick and easy way. I can't say that I've noticed any big difference in taste. To me the most important part that no one ever talks about is how to use your nose and taste buds as you are cutting up the tomatoes to throw any portions out that don't smell or taste good due to being overly ripe, under ripe, or rotten.