FINDING AND AREA
The first thing every you must do is find a location for your boxes. You need to decide whether or not you have space for it on your property. If not you can organize a communal space where anyone can grow and harvest vegetables. You will want to make sure your location gets get sun and won't be disturbed by anything.
MATERIAL FOR BUILDING YOUR BOXES
There are few materials needed for building a garden box. The first thing you need is wood. You can find wood almost anywhere. You can go to places like Home Depot or Lowe's. If you are buying from large retailers like these you should expect to pay around $75-$125 for 1 box, $150-$200 for 2 boxes, and $225-$275 for 3 boxes. You will also need soil or dirt This can be found almost anywhere as well. You will need any kind of drill and screws to connect everything together.
ALL ABOUT THE BUILD
Building the boxes is the hardest part of the whole project but still very easy. The first part is to figure out what you are planning on growing in your boxes. If you are going to grow vegetables with small short roots such as spinach or lettuce, you will want to get 3 pieces of wood that are 8-10 inches tall, 2 inches wide, and 8 feet long. You will use 2 of those for 2 sides. Cut the 3rd one in half to get two 4 foot, long boards. You will also need four 4-inch by 4-inch blocks to use as joints when connecting the boards together. If you are planning to grow vegetables such as potatoes or carrots you will do these same steps but get 12-16 inch tall boards. When getting soil, go to any local yard waste company to find compost and soil. Once done putting the wood to whether to make a rectangular box fill it up with your soil or compost.