Do you scald your tomatoes before peeling them?
Drop a whole tomato into boiling water for 15 to 20 seconds (you will need to experiment with the timing) - take the tomato out of the water and put it in cold water.
The skins peel off very easily this way.
If the skins don't come off easily, leave them in the water for a few seconds longer. If the top layer is mushy, leave them in the water for a few seconds less.
You can peel the tomatoes and then squeeze a lot of the seeds out - if you want, you can squeeze the juice and seeds in a jar and strain the liquid out. Sometimes they say to remove the seeds to get some of the extra liquid out and the sauce will be thicker.