Help for writing boring, important bits!

Hey I plan on starting a book and I have this kick ass idea but I am facing some problems.
I have this world based on this complex caste system and these set of rules and regulations (somewhat like a list, like the ten commandments). And all the caste and the rules are fictional and aren't based on any of the society or religions.
So how do I put these things in the book without making it boring?
Any advice or any suggestion? Any book I can read that will help?

To put it simply: there should be no boring, important "bits".

Providing the reader with essential worldbuilding info can be tricky. My first question for you is about your world itself. You say this caste system is fictional and not based on any of the societies or religions. If it's fictional, why does anyone in your world abide by it? Caste systems are by there very nature a part of the society/culture that they exist in. If you mean that the caste system is not based on any of OUR real life societies or religions, that doesn't matter at all. It's YOUR world, not this one. Making comparisions to Hinduism or Sihkism within your story won't mean anything, because those religions do not exist in that world.

The biggest mistake people make, young writers and published authors included, is the infodump. The infodump is a section, sometimes even an entire chapter, that is nothing but explaining a concept that is important to the story. Usually it's done by forcing your characters to participate in contrived conversations about basic elements of their culture that they have no need to explain or discuss because the things they are discussing are an everyday part of their lives. It would be like two characters in a novel set in real world America discussing the history and traditions of 4th of July with each other just so the author can make it clear to non-American readers.Or even worse, it's a huge internal monologue of the main character literally thinking about aspects of their culture that they would NOT be thinking about in such an explanatory way. Christopher Paolini is super guilty of this, so hes a perfect example of what NOT to do!

Readers are smarter than many writers give them credit for. Instead of TELLING readers the details of the culture, infuse the culture's practices into the characters' ACTIONS. For instance, say in your world your MC is a member of a lower caste and he/she is in a situation to interact with someone of a) a caste one step up from theirs and b) someone of the highest caste. Instead of having your character internal monologue about the castes and the meaning of the clothes/markings each wears, SHOW us that person A and person B are higher than the MC by having the MC react to them in a way someone of his/her caste would react. If say, they are required to not make eye contact with someone from person A's caste, have the MC do this and DO NOT explain to us that "MC was required to lower her eyes; Person A was of the Caste X, the one just above her own". We will gather that it's a cultural custom. And if the reaction to the highest caste is to lay flat on the ground, show the lower castes doing this. We will infer that the fat man in gold is a ruler based on his a)wearing gold and b)everyone bowing to him.

Sci fi books are usually good examples, because even if they take place in our world they still have to present a lot of foreign ideas. Pushing Ice by Alastair Reynolds was particularly good at this. By 10 pages in, I had a full understanding of when the story was taking place, what the rankings on the ship were and their jobs, and how the technology functioned all from natural conversation and action between characters. Margaret Atwood is also really good at this, especially in her Madd Addam books (Oryx and Crake and the Year of the Flood). You learn all about this complex post-apocalyptic world and it's politics and religions just by seeing the characters' experiences.

Aurora was quite thorough in her reply, and she brought up a lot of good points.

Just to add on to what she's already mentioned, you also have to weed out the bits of information that aren't essential for the readers to know. For instance, there is a holiday involving x type of celebrations which your characters are attending. Do we need to know the whole history of the celebration beginning from when it was first celebrated? Probably not. Do we need to know every detail of the ceremony/celebrations? Again, probably not.

Now if, for instance, the reason why the celebration is celebrated is important to the plot (like it's a cover for a secret society that guards an artifact of great power), then try to slip that information in as plausibly as possible. Since it's a celebration, having a play or some other performance about the origins of the festival would make sense. Again, though, you have to weed out unnecessary information. Do we need a whole chunk of text devoted to the play? Probably not, but you can mention the play and it's subject. Depending on the point of view you're writing in, you can have your character think about different aspects of the play ("Y couldn't remember the last time the play had been performed so well. The actor playing Z had been so convincing, especially at the moment when he retrieved the Artifact.") or you can mention it in passing in the narration ("After the traditional play about how Z had retrieved the Artifact and hid it near the town...").

Basically, pick out only the most essential pieces of information that the reader absolutely needs to know or else the story won't make sense. Then, incorporate these pieces of information as naturally as possible into your scenes. Streamlining your writing like that will make it easier to read, and more interesting.