There are many resources on the market. The list below includes just some of my personal favourites.
Gardens West Magazine www.gardenswest.com
Fine Gardening www.finegardening.com
Garden Design www.gardendesign.com
50 High-Impact, Low-Care Garden Plants by Tracey Disabato-Aust
What’s Wrong With My PLANT? (And How To Fix It) by David Deardorff and Kathryn Wadsworth
Succulent Container Gardens by Debra Lee Baldwin
RHS (Royal Horticulture Society) A-Z Encyclopedia of Garden Plants by Christopher Brickell