Enumeration, the genitive, and который--please help

Good evening! I am teaching myself Russian in preparation for a vacation there in September. I have been taking several different on-line courses and watching whatever I can find on YouTube. So far, I think it has gone well, but, of course, I have a number of questions, and hopefully the members of this board can help me with them.

First, from what I can gather, it seems like any time you are talking about a quantity of a noun, the noun is in the genitive case. For example, to say "I have many books" would I say "у меня много книг"? Or to say "there is not much work" would I say, "нет нeмного работы"? I have no idea what the rules actually are or if I am even close to being correct. I would appreciate it if somebody would explain how this really works.

Secondly, I truly do not understand the word "который". It seems to be used to mean which, that, who, whom, and what, but I can't tell how or when to use it properly. I am totally lost--can someone please help?

Thanks to everyone in advance!

Hallo, Blackdog)

When you say "I have many books" and put it "у меня много книг", this is absolutely correct.

When you want to say "there is not much work" you mean technically that you don't have much work to do, or that not much work is needed here, am I right?. The difficulty here is that in Russian we don't have 'there is' construction and our expression of negation is different. 'There is' implies some possession, existence of something. So "there is not much work" can be done as 'У меня немного работы' when you specify you don't have much work, or 'Тут немного работы' which is literally 'Here there is not much work'. It can also be shortened to just 'Немного работы' in which case you and other participants of conversation understand what work you mean and what you are talking about. Here, much depends on the context, which will make one choose the proper phrase in Russian.

Now, concerning 'который'. It is a universal word for 'which, that, who, whom, what' and so on. The problem here for you will be the declension of it.

I could make up some examples for you showing that it's actually universal.

The man who stands over there. - Человек, который стоит там.
The car which belongs to me. - Машина, которая принадлежит мне.
The money that I want to take. - Деньги, которые я хочу взять.

It's a difficult word, for sure, to put it simply, just use it as INDICATING word, and you won't miss. Later on, you'll have a better understanding of it, now just think of it as a tool for indicating something.

"kotoryi" means "which/who/that". But unlike the English "which" it changes according to case and number. For example you might say "Gorod v kotorom teplo" (prepositional case, masc.) "A city in which it is warm." or "Goroda v kotoryh teplo" "cities in which it is warm"

Another complication is that the word "kotoryi" and the noun it refers to can be in different cases. For example:
"Ol'ga - devushka, kotoruyu ya lyublyu" - "Ol'ga is a girl that I love" Here "kotory" is in the accusative case because it is the object of the verb "lyubit'". (In fact, in old-fashioned English they would say "Olga is a girl whom I love").

There are even more complicated examples: "rasskaz o lyudah, kotorih net." - "a story about people who don't exist" (lit. "of whom there are none") here "lyudah" is prepositional plural and "kotorih" is genitive pluaral.

Like the previous poster mentioned, in order to use this word correctly, you will have to speak and read Russian extensively for a number of years.

"У меня много книг" is literally "I have a pile OF books". That's why we use genitive.