It all depends on your taste in applesauce. Here is what I just finished with: Quarter and core apples (cut quarters into half if larger apples), filling a 10 qt. heavy metal pot. Place on medium heat with about 3 cups of water and cover. Let simmer until apples are softening and settle down in pot. Add more apples back to the top of the pot, let simmer longer until apples are soft. Remove from heat and fill quart canning jars to about 1/2-3/4 inch from top, clean rim and seal. Place in water bath canner with hot water, add boiling water when finished to cover jars at least 1/2 inch. Boil gently for proper processing time, about 25 minutes at my elevation (4500 feet). Yields about 7 quarts.

I also made some sauce in which I used 4 cups syrup as the starter (1 c. sugar to 4 c. water). Sweetening will vary depending on how tart your apples are and how sweet you like your sauce. You can also add some spice if you like it in the sauce, such as cinnamon. I prefer my sauce without sugar, then when served if people like sugar it can be added as can a dash of cinnamon.

I use yellow transparent apples. They will remain chunky in the applesauce and the skins add texture to the sauce and are soft enough you won't think they are pieces of cellophane.

I make apple sauce to taste, no real recipe.
Cook the apples down. For smooth sauce (or hard apples) run a stick mixer through it, for chunky don't (but don't use hard apples that don't like to cook down).
Sweeten to taste. Cinnamon to taste.

I pressure can. I can do 4qts at a time so that's what I keep my batches at (about 3 1/2 lbs if I remember right).

If you're not going to do any kind of canning they'll probably go moldy pretty quick even in the fridge. Only make enough at a time that you'll finish quickly.

You don't need to pressure can apple sauce if you use a little lemon juice (4 tbsp to 12 lbs apples). You still need to hot water bath process though, 20 minutes submerged in boiling water. Sugar and cinnamon to taste. I like using cortlands and I leave the skin on and then strain it out after cooking. It makes it a pretty pink color.

I didn't say pressure canning was needed, I said I did it that way. It takes half the time of boiling.
Neither way requires lemon juice, at least not at the time of my USDA sheets.