Amy asked for my tomato sauce recipe. My neighbor was making some and explained her process to me, so this is straight from her kitchen.
Place your tomatoes on a baking sheet (I recommend one with sides to catch the juices) and slow-roast them at 225 F until they are mushy inside. Take them out to cool a bit, and the skins just slip right off of them. After removing skins, put the rest of the tomato into a big saucepan, remove any core if need be (or presumably you could do this before roasting. I just got my hands in the goop and took out the cores that way.) Cook the tomatoes down until the sauce is the consistency you want - longer cooking times for thicker sauce. Season however you'd like (I use garlic, basil, rosemary, and oregano).
If you're going to can it, most sites recommend adding vinegar or lemon juice to increase the acidity and prevent problems, especially if you're using a sweeter variety of tomato.