Hello Carl and thanks for your question.
One of the best resources for determining what types of plants work best in many parts of the country is the Better Homes and Gardens Western Garden Book. This is the "bible" for many home and professional gardeners as it provides information about every type of plant that you might wish to buy, including best locations to plant the shrubs, ground cover and trees, and the type of fertilizer and soil that works best.
Depending on the area where you are proposing to plant flowers, I find that annuals (those that live only a short time and must be replaced later) provide the "showiest" and most colorful displays. Perennials, which can last from 3-7 years provide flowers during certain times of the year, and remain green and viable throughout the year. Some plants, such as Bouganvillias, Clematis and Trumpet Vines provide excellent blooms, but are best on a trellis. Ground cover perennials such as Gazania and Vinka Minor take full sun and provide blooms in many different colors, and can be "popped" in color by the addition of bulb plants such as Tulips. Society Garlic also provides great color with stalks of purple flowers and white frosted leaves, and can take full sun, but I find that the plants--like their garlic namesake--do have a pungent odor, so use these sparingly.
However, to get the best plan for your landscaping, start with the Western Garden Book for ideas, helpful clues on planting, and detailed plant information.
Grace Morioka, SRES, e-Pro
Area Pro Realty