I love, love, LOVE fresh, homemade tomato sauce!! I grow at least 14 tomato plants every year, can a ton and make as much fresh tomato sauce as I can eat.
My method: Blanch tomatoes as indicated above. Slip skins. Cut in half cross-wise (NOT from the stem down, but through the middle of the tomato). Squeeze out seed pulp. Throw skinned, seeded tomatoes into a saucepan with a wee bit of olive oil. Cook gently until preferred thickness is achieved.
For a fabulous quick sauce, cook for a mere 5 minutes with a little virgin olive oil, a couple of crushed cloves of garlic and salt and pepper to taste. Divine!!
I blanch and skin them first, then stick them right in the pot and mash them a bit and let them cook for a looong time. I add olive oil, a pinch of salt, some pepper, and fresh herbs from my garden (thyme, oregano, basil of course!)
I've never understood when people add sugar to their tomato sauce- to "cut the bitterness"- I have never had an issue with bitterness in my tomatoes! I HATE the sweet taste, which seems to permeate most store bough sauces. Gross.
this is the easiest way but not the finest; otherwise they all work out equally well,
Barely-cooked tomato sauce is best when tomatoes are at their ripest. Briefly cooking the sauce helps retain the tomatoes' fresh, tart-sweet taste, but also heats them long enough to add depth of flavor. Caramelize some onions, sauté garlic, and simmer herbs long enough to infuse the sauce with their flavors.
I have done it severally
Roasting them gives wonderful flavor! Quarter the toms, drizzle w olive oil, season w salt, pepper and add basil - fresh if you have it. Roast @ 400-425 for 20-30 mins (add onion, zucchini, dash of balsamic etc, it's all good), or slow roast @ 225ish for about 2 hrs (these are then more oven-dried, but beyond delicious!). Stir into pasta....
Love It too
this is the easiest way but not the finest; otherwise they all work out equally well, 
