Raised bed gardens are a great way to start gardening without a lot of the pain. You can either make a raised bed garden from scrap materials, or build one from kit. Here's a look at some of the options.
Some of the biggest problems with gardening are finding a good spot with good soil to get started, and the ongoing need to spend a lot of time in the garden bending and stooping to prepare the soil, and weed the garden. In addition to this, you may have issues with your soil like poor drainage or soil borne diseases. One way to get around most of these problems is to use a raised garden bed.
One other advantage to using raised gardens is that the crop yield will tend to be higher because you will be using intensive gardening techniques like wide row planting or square foot gardening. This cuts back on the amount of watering and fertilization needed for gardening as well. You can get higher yields because you don't need space for the rows to walk in between plants, and the closer spacing of the plants helps suppress weeds. In addition, since you aren't walking on the soil, your avoid soil compaction, so over the years you enhance the root development of your crops.
You can build raised bed garden yourself from scrap lumber, although you may find that your scrap lumber doesn't hold up as well as more expensive wood like cedar. If you choose to build your own, one common way to simplify the job is to use raised bed corners. Making sturdy corners is the hardest part of the job of building a bed, and these cut out a large part of the job. They also make it easy to stack boards to increase the height of the bed. With these you can easily tailor the bed to your specific needs, even building a bed that has some shape other than rectangular. Hex shaped beds are a popular option, useful for building around a featured item in the landscape like a tree or a flagpole.
If you want to buy a raised bed garden kit, you'll find that cedar bed gardens are some of the most popular. Cedar is a long lasting wood, it resists insects well, and is quite attractive. These beds are also found as raised planters, and beds raised to almost waist height can really eliminate the pain associated with working in the garden. Add a small platform underneath, and you don't even need to walk to the shed to get your tools.
For something a little less expensive, take a look at the vinyl or plastic bed kits. Some are made from recycled plastic, and come in a number of colors so they can blend with any yard. The brown is often fashioned to look like a real timber bed, but come in sections that can be extended.
For an interesting change of pace, some plastic raised beds are built to look they are built from rock. Coming in straight or curved sections, they are made of a lightweight composite, but appear as natural rock. Much cheaper and easier than rock, but definitely a change of pace from traditional raised gardens. These typically come in gray finish.