Keep an eye out for any photos in magazines that catch your eye. Perhaps your local thrift store has a good selection of cheap magazines that you can use as research. Gather you a stack and cut out anything you see that sparks a landscaping idea. Try an online site such as Home and Garden TV. Search for the section entitled "peaceful backyards" and you'll find photos of some lovely landscaping for the backyard. You can find The Essential Garden Design Workbook on Amazon, or have it special ordered at your local bookstore. Better Homes and Gardening has a book entitled Step by Step Landscaping. You can order it on Amazon, along with many other good titles.
Landscaping doesn't have to be a huge undertaking. Spicing up your yard could be as simple as planting bright, fun flowers. For a relaxing backyard "getaway" consider a small flower garden with decorative touches, like an engraved stone. If you are really ambitious, you could add a small "waterfall" in the middle of the flower garden. Fountains and ponds, if you have the space, are both excellent for relaxation and eye candy. Talk with your landscaper about what types would be ideal for your back yard. I love the look and feel of a flower garden with a stone path that winds around the flowers. If you have the space, you can make a beautiful flower sanctuary for your family, right in your own backyard!