You cannot say a/an with an uncount noun. You cannot put a number in front of an uncount noun. (You cannot make an uncount noun plural.) You use an uncount noun with no article if you mean that thing in general. You use the with an uncount noun when you are talking about a particular example of that thing.
You can put a number in front of a count noun. (You can make a count noun plural.) You can put both a/an and the in front of a count noun. You must put an article in front of a singular count noun. You use a plural count noun with no article if you mean all or any of that thing. You usually use a/an with a count noun the first time you say or write that noun. You use the with count nouns: the second and subsequent times you use the noun in a piece of speech or writing when the listener knows what you are referring to (maybe because there is only one of that thing) You use an (not a) when the next word (adverb, adjective, noun) starts with a vowel sound.
The guideline said "You use a plural count noun with no article if you mean all or any of that thing."
For example, "I read books" means I read all books or any book that I have, doesn't it?
The site didn't mention the rule of "using a single count noun with no article". That is where I confused.
So, it can deduce that "I read book" is grammatically wrong, right?