I want to learn how to clean manga raws. I have a very very basic idea about Photoshop so I wanted to know if there is any website which explains/teaches cleaning right from scratch including how to work with layers. I tried out some of the famous scanlation guides but they don't really explain how to work out with the basic stuff on Photoshop (like how to remove text by adding another layer and not solely from the background layer... wait I don't even know if that is possible) so they weren't of much use.
Thanks in advance!
Edit: Just realised the heading should be "Guides to cleaning manga raws".