When you write you want it to be interesting. You want people to read it and LIKE it. You want to describe events crystal clear so they are easy to understand and so they will give the reader a good picture in their mind of whats going on.
When you start a book, most of the time it is boring. Usually the first few chapters of a book are used to introduce the characters but there is a way to brighten it up a bit. What you can do is start it with some action. This will grab the readers attention and will want to make them read on. (Warning: Do not have the book too full of action. You will eventually run out of ideas and your book will be left unfinished.)
Don’t ramble on about one detail. This is makes it VERY BORING for the readers because they get the concept of the idea. So you want to be basically short and sweet.
You always want to have a twist. The reader will think they know what is going to happen but when they read on and find out they don’t it will make them more interested and make them want to read on.
One last thing. NEVER HAVE TO MANY CHARACTERS! This confuses your readers a lot and they just give up on reading because they usually will have to go back to the beginning of book to see who each character is which and this usually is very boring and makes them stop reading.