I'd like to know your insights are some good, concise books/websites/resources on vitamins and minerals.

A few good ones I like include:
Idiot's Guide to Vitamins and Minerals
PDR guide to nutritional supplements
vitamins & minerals demystified
Superfoods for dummies
Wellness foods A-Z (UC Berkeley)

I'm wondering if there's anything else you guys can add?

Without a doubt the best and most comprehensive book I have seen on vitamins and minerals is Dr Atkins Vita Nutrient Solution-Natures Answer to Drugs. I think you can get a copy for about $5 on Amazon. Slightly out of date on the latest research on such subjects as Vitamin D(it was written in 1998), but all the basics are comprehensively covered.

https://www.amazon.com/Dr-Atkins-Vita...9&sr=1-1-fkmr0