All help in this regard will be appreciated. I have been reading books on the subject, but none reduce the wine making down to a step-by-step process.
Before diving into frozen grape must, I suggest learning what additives are used, why, how much is used, and what they do. The wine making process will make much more sense and you will end up with a better wine in your glass.
Second to that, I strongly suggest leaning into a working knowledge of the biology of yeasts. For example, there are differences of how yeast cells begin their journey making wine. Dry pitching (what most kits tell you to do, and actually not recommended for most yeasts), making an 'overnight starter', and using hydration nutrients all affect the outcome of the final wine different ways.
Many, if not most, will disagree that DAP (diammonium phosphate, aka "yeast nutrient") should only be used under certain circumstances. When researching, you'll find that DAP used in wine is actually food grade agricultural fertilizer. If digging deep enough, you'll find that it's not a nutrient as most think it is. Other commercial nutrients are available to home winemakers that have more benefit to what is in the glass.
Three excellent sources of information are available for a start:
The Scott Labs handbook. It's a resource for home wine makers as well as commercial businesses. Tons and tons of information. Pearls of wisdom are scattered throughout the manual that crush many of the rumors on the internet and in some books.
https://scottlab.com/content/files/documents/handbooks/scott labs 2024 winemaking handbook.pdf
Two wine making links:
This one is a complete tutorial, page 1 of 6:
https://winemakersdepot.com/Tutorial-on-Wine-Making-Lesson-1-of-6?
I seldom recommend YouTube videos because most leave out important details or are simply wrong. This one is about as complete as it gets: Part 1 of 3:
The guy's YT channel also covers many of the methods, additives, and reasons to use them.
All the best,
Barry