Newbie Question - Checklist of images and dimensions needed

Hi all!
I’m a total newbie, and starting with Infusionsoft from scratch. My business is also very new, so I’m creating many of the images brand new.
As I go through the setup process, I come across requirements for various logos, headers, footers etc whether its for internal system use, thankyou pages, automated emails, external campaign emails etc. But there doesn’t seem to be any kind of “new user quick start” list, so as I come across the need for an image, I’ve been writing it down so I can brief my graphic designer all at once - but I don’t think it always specifies the “gold standard” size/ pixels that are recommended for each instance.
Has anyone come across any kind of graphic or image checklist? Something itemising the generally required images, their use, pixel size etc - I’m sure there’s more that I haven’t come across yet!
Thankyou for any advice!
Donna.