Another good book (out of print so you will have to search for a copy) is Sign Structures and Foundations "A guide for designers and estimators". it was a Signs of the Times book and the author is Peter B Horsley. The copyright date on mine is from 1984. I did a quick google and there are some copies out there.
It's a great book to help you to get basic footing, wind load, etc. calculations using basic math - no calculus required. Way back when we road dinosaurs to work, I made a spreadsheet using it and have been using that to get me pretty darn close for freestanding signs for many moons. Of course no engineer I've ever asked about my spreadsheet will even respond. After all, I don't have that piece of paper and so can't possibly be able to do math. ?
It also goes into lighting design but of course doesn't have any info on LED's.