Led’s and other stuff is a good spot to bookmark. It includes many pages that I had bookmarked separately for ages.
One stop mod reference shop Has a ton of useful info.
BLF modding links thread Has mods by many of the favorites. But only by those who took the time to put them there.
Tint, binning, CRI explained Obvious.
BLF first annual DIY contest If you read this and still can’t think of anything. Quit.
These are examples of resources I use frequently but in reality they did not exist when I was learning a lot of this so I just bookmarked my favorite stores, the Cree website, data sheets for 7135’s and Attiny13A’s and whatever else I was researching at any given time. It’s called studying, and if you didn’t learn how in school then you have to learn how to learn now. Whatever works for you. For me it was a smattering of this and that mixed in with plenty of erroneous assumptions on my part graciously(or not as the case may be) corrected by others and lots of questions. Even now I still spend far more time reading than anything else.