When I was signing books at the Leamington Peace Festival on Saturday 18th June, a young man came up to my book stall and started chatting to me about writing books; it turned out he was writing a book himself and wanted any advice I could give on the best way to start a book. 
My advice was particularly tailored to writing a novel but of course it’s relevant to any book targeted at a commercial audience.
The beginning of a book must have some kind of emotional charge. It has to hook the reader in the first paragraph or first page. In the case of a novel the best way to start is with a scene of conflict in the life of your main protagonist. This scene needs to show where your MP currently is, in their life, and what the tensions are in their situation.
One of the courses I took a few years ago covered story structure in terms of the 7 point arc. I remember it mentioned that you begin a story with Stasis – in other words, where the MP is right now. Then there is an Inciting Event – in classic story structure of myth and legend, the MP receives a call, which will move him or her out of the ordinary world, into a new world. The MP can either accept this call or reject it. Either way it is the invitation to a quest. There are many ways of illustrating story structure, using different metaphors but The Hero’s Journey is the best to my eyes. It sets out the structure of a story in terms of classic myth or fairy tale format. And it makes big sense to me.
Many novelists find one of the trickiest things is to know Where to Start Your Story. Finding out that key moment is a great challenge. You may not discover it until you’ve written the whole book. I advised the young man not to worry about it too much but to write the book all the way through first, because inevitably he will go back to the beginning and probably rewrite it several times. You can often only find out where your story starts, that moment of tension, after you have written the story.
Sometimes the story may start three chapters later than you through it did, and you will need to cut out your first chapters entirely. Or maybe it starts further back. Either way, it can be very exciting and revealing, when you find that perfect point where your story starts.
If you’re writing a novel, I welcome any thoughts you would like to add to this subject, in the comments.
scskillman.com 
I agree that you need a hook in the first few sentences. It may be something that is left open-ended which has more substance and clarity added to it much later on in the story. Maybe something, a discovery, that triggers a memory in the MP, which motivates the main story line.
The other piece of advice that I give to wannabe writers, and I am somewhat of a novice myself so it is a bit of a cheek, is to READ a lot! A young man that I met recently told me that he hardly reads at all. I told him that, although it may sound harsh, he would never write anything that was any good if he did not read. I strongly believe that I am right.
Yes I agree with that Lance. I believe it is important to read widely, not necessarily in your specific genre, though some writers might disagree with me on that. I heard a few interesting replies when I asked people at my recent book-signings “Do you like reading books?” The answers ranged from, “Oh no”, “I never get the time”; and “the only time I manage to read books is on holiday” to “Don’t read, can’t read” and “hardly ever get the time to read books, what with 2 children and a dog.” I think we all make time to do the things we really care about. I admit I read books instead of watching TV. Sometimes of course that means I might miss out on some fantastic TV programmes but my 18 year old son is very good at keeping me up to date with excellent drama mini series and documentaries that I can catch up with a few days or weeks later on iplayer!