Making A Raised Bed With Straw.

One of the easiest ways to make a raised bed garden might be with using straw bales as the border and then filling in the raised bed with leaves, compost, and whatever dirt you want to use for planting. Since you can also plant directly into the straw, it is totally optional whether you want to use the straw as a border, or just lay out some bales of straw and plant your garden in them.
How large an area you want to plant would be a good way to decide whether to also plant a raised garden inside a border of straw bales.
Hay bales can also be used; but they usually cost a lot more than straw does, they are a lot heavier, plus they are usually full of seeds that will sprout right up into your garden. Straw bales come from grain (wheat, oats, barley, etc) that has already been threshed; so there are very few seeds/grains left in the straw, and whatever does sprout is easy to weed out.
On the other hand, hay bales have a lot more nourishment to help plants grow than straw does, so this might be a consideration as well. Either way, you need to either get your bales in the fall so they will be ready for planting by spring, or you need to start soaking them every day in the spring so that they will start to rot inside.
There are some interesting youtube videos on growing a straw garden that will help the beginning gardener, and I would suggest watching a few to see which method would work best for your garden area.
Another really nice thing about growing plants in a straw garden is that is is higher up off of the ground, and easier for a gardener to do any necessary weeding, especially when you have a bad back.