After washing the tomatoes, I put them in boiling water for a minute and then transfer them into a bowl of cold water. This makes the skins very easy to peel off. At this point you can freeze them in bags, can them, or continue on to make a sauce. Some people also remove the seeds, but I don't do this.
You can either throw them in the blender for a smooth sauce or you can chop them up and throw them into a pot to cook down into a chunky sauce. I add garlic, olive oil, rosemary, salt, and pepper early on in the cooking process and closer to the end I add some basil and oregano, sometimes some thyme as well. I think the amounts are a matter of taste, but I am not a real recipe follower, so Cathe's advice might prove more helpful for you.
NOTE: I find it is often easier to start from whole peeled tomatoes, either from a can or ones that a prepared at an earlier time.