Western Garden Book is a great source of information. I get a lot of information from Learn2Grow --
http://www.learn2grow.com/plan... ; Monrovia --
http://www.monrovia.com/plant-... ; and Proven Winners --
https://www.provenwinners.com/... (Okay, I admit I go to the Proven Winners site mainly to look at the pictures).
When you're composing a data proposal, it's good to put yourself in the position of someone who'll be searching for plants with specific characteristics. A person searching for plants with white blooms for a moon garden, for instance, will not want the results to include red, blue, and purple flowers with just a touch of white. A person searching for plants that grow to 3 feet tall can confine the searches to 3 feet and 36 inches and will not have to also look for 3 ft, 3', 36 in, and 36". I personally like red blooms, but I like the red to be complemented by another color rather than being solid red, so I can type "red" into the Bi-Color field and the "Multi-Color" field and find lots of the blooms I like.