Can some clarify about how to use darueber. I am somewhat confused . I know in this sentence you can use it to describe a conversation or book in regards to it's contents. However, you can also use it in a manner for location too. Ueber is also used location too right? Can you also use it to describe o describe a conversation or book in regards to it's contents too? Aslo herum is only used for location right?
darüber: over that, about that.
If you talk about position über will mean over.
- Ich springe über den Zaun = I jump over the fence.
- Da ist ein Zaun. Ich spring darüber = There is a fence. I jump over that
As you can see the darüber does not point to fence in the sentence itself. It is a word like this and that. You know by context what it refers to without pointing to the noun itself.
If you talk about abstract things you can talk about you can use über, too.
- Ich rede über dich = I talk about you ( The case is important here, because if you use dir, you will mean that you are standing above someone while talking)
- Das ist ein Problem. Ich rede darüber = That is a problem. I talk about that.
I hope this gives you a general idea.
About your question with the content. Most common is: Das Buch handelt von ... But you could say: In dem Buch geht es um.
Some people might say that you can say: Das Buch handelt über ... but I am not sure about that. You can find people who will disagree but also who agree. Duden doesn't mention it clearly but you can use über to speak about the content you wrote, you talk about.
Mein Text über dieses Thema ist beliebt = My text about this topic is popular.
Many German speakers kind of swallow the "r" when it comes before a "d" like this. Mostly well-spoken university students, so it's likely a good thing to copy.
(It's good to notice how and when Germans pronounce their r's; they often elide them or place them very differently than we would when speaking English. So Americans speaking German can sound very RRRR to the German ear.)