I'm glad you're you having healthy cravings!! Don't you just love it when you're sitting with a bunch of people and someone's like 'oh man i wish i had a bag of chips right now' and you smile dreamily and are like 'mmm watermelon'
For the nutritional properties you could try
www.calorie-count.com... they have tons of junk but they also (usually) have the raw version, and they have a complete analysis of all the nutrients and how much (ex. i used the info to prove to my parents that a banana had all the essential amino acids in greater or equal amounts as in an eggs).
That's so funny for the last week or so I've madly been eating califlower and watermelon!! Mmmm I wish I had a watermelon now!