Reading a Book
I am reading a book right now, a knowledgeable book [Possibly you mean a non-fiction book?]
I have just started to read at the beginning but I feel it bored, yet but I have to finish it because I have to understand what it is all want to tell about.
Reading a book
I am reading a well known book right now. I have just started to read the beginning, but I feel it's boring. I have to finish it, because I have to understand the storyline, in order to talk about it.