Many people know this already, but I find step-by-step instructions useful, so maybe this will help someone just starting out. To start with, I put down a piece of rubbing roofing, and hold the edges down with stones. You can use whatever you have to cover the area. The area is 15 by 24. I like to start gardens approximately this size because it is large
enough that you can grow a substantial amount of food, but small enough that it is easy to keep up with and isn't overwhelming. I left the rubber down about a year because I have quack grass, and I want to make sure it is completely dead. If you get an area covered now, it will be ready for next spring's garden.
Immediately after removing the rubber, my hard clay soil is soft and easy to work with, thanks to
ants,
voles, snakes, and other creatures that live under it. You can rake it easily, something that will be impossible shortly. I never undercover the area I am working with until I am ready to use it. Leaving it exposed for even a day can bake it into a brick again. This is how it looks immediately after removing the rubber and giving it a light raking the smooth out the ant hills.