Some of the other benefits of raised beds are: reachable - less bending and stretching gives the gardener easy access and makes maintaining and harvesting less of a task to perform; drainage - because the soil is above the ground it will not become compacted during heavy rains and will drain properly in preventing water-soaked soil;
Another approach is to use concrete blocks, although less aesthetically pleasing, they are inexpensive to source and easy to use. On the market are also prefab raised garden bed solutions which are made from long lasting polyethylene that is UV stabilized and food grade so it will not leach undesirable chemicals into the soil or deteriorate in the elements.
When growing vegetables in raised garden beds using the Square Foot Gardening method, your beds will need to be sectioned off into one-foot sections called planting squares.
For instance some companion plants for your tomatoes are onions, carrots, and parsley while cabbage and cauliflower need to be kept away. Be sure to rotate your vegetables every year, if you planted tomatoes in the green bed last year plant them into the red bed this year.