When do i need resistors?

Hi everyone,
I tried looking this up, but I can't really understand the info, since it seems it's subjective. Basically, I'm interested in replacing all my bulbs (minus the dash) with LED/HID bulbs. Just to spruce her up a bit. Now I see that resistors are recommended for headlights, right? Are there any other bulbs I should be using resistors for? Or, can I run a single resistor to cover a whole side?

My wife had a 2014 civic. We tried some ebay LED bulbs and got those DRL warnings. I just don't want to get any warnings at all. Lol. So, I'm trying to see what I need to have on my list of parts before I go buy something and then realize I need something else,etc.