Three Things You Need To Know About Your Novel Before You Start Writing It
Ask yourself, who is your story about? What drives them? What do they want? And then ask yourself, what obstacles can I put in their way to stop them getting it, and to delay any eventual resolution?
This formula, as well as helping you to shape your protagonist, will also provide you with the bare bones of your plot.
Speaking of plot, it is always a good idea to have at least one "event" in mind, something that you can build up to as you are writing.
This will give both you and your narrative some much needed purpose - though who is to say that it has to be a straightforward and linear journey? (Do you remember those obstacles I was talking about?)
To reassure all you "explorer" types out there, pre-planning your destination does not necessarily preclude the possibility of some spontaneous diversions along the way!
The final thing that you really need to know is where and when your story will be set, as this will dictate the rules and the social conventions that your character will be expected to conform to.
(Having them defy such expectations is an excellent source of conflict, but that - as they say - is quite another story.)
The old aphorism is, of course, to "write what you know", but if that does not appeal, do make sure you do your research on the time and/or the place that your novel is set; and, if you are constructing a world that is entirely alien to the one in which we currently live, try to go more than surface deep with your creation - think carefully about all of the factors that contribute to our view of our world, and then try to replicate those in a way that is relevant to your new one.
(For more tips on successful world-building, don't forget to check out next month's edition of The Write Stuff!)