Do I need to shut down my UnRAID server to add new drives? I think I do but, want to be sure.

physically yes, everytime

 

use greenshot to catch an picture of the main page so you know which drive is parity 1 - ?

I put stickers on my drive with part of the serial number on the back & side eg sea 2tb 5640

It's a good idea, but not required. All that is required is that the array be stopped to add a new drive. Especially if you have hot swap drive bays. Plugging in a new drive will allow it to show up and be added to the array without a reboot.

If you have a parity drive, then you must preclear any drives to be added so parity will remain valid, or unRAID will clear the drive itself and take your server offline while it does so. It's better to preclear so you can test the drive.