In a big garden that sounds like a lot of work, DirtMechanic. I would start off with a small square where you want to grow something, make a wall around it with the rocks and then mow the rest and chuck the chopped up stuff into the square to rot, make compost and add to the earth. The rest of the garden will look better flattened and you can gradually extend your growing area. A compost bin for al your kitchen waste would be a good idea as well. If you add anything that could make earth in the long run, the contents of the hoover bag, dust you sweep from the drive and patio, autumn leaves, everything, it is amazing how quickly you can build up a patch of fertile soil. My garden slopes slightly north and is really heavy clay in some places, one bit I dug out about a foot deep and used the clay to make a wall along the north side, after a year I have a bed with a slight south facing slope about 10 foot by 6 foot with a good eighteen inches of good soil that I have just planted out celariac in.
Basically, little and often kept up continuously will get you there, try tackling it all at once and you will kill yourselves and be discouraged.
...think I'll go n put the kettle on.....
