You have been building up the characters for your novel in your head for months, maybe even years and you want to introduce them to your readers with as much detail as you can. However, it may not be the best idea to tell all that you know about them in the opening chapter or two of your novel.
Write down all the character details as well as the setting details that you have stored in your head. As you write your novel, reveal things about the characters and setting a little at a time. If you include everything you know about the characters and setting at the beginning of your book, it will overwhelm the reader and possibly even bore them.
The key is to reveal this information and these details at just the right moment throughout the book. This will keep your readers engaged, connected and looking for more as they read on.