I am working on trying to make my own plymouth boot screen, but the internet doesn't seem to have that many articles about it. I was hoping someone could give me a crash course on what to do to make one. What exactly is needed and has to be edited? Thanks:)
Check this link for general plymouth info. In particular take a look at the "External Resources" section at the end of the page for links to tutorials etc.
Also, take a look at this page for an intro to the Plymouth scripting language: