Blowing Life into A Story

I've been working on the characters I need for my second novel. When I started my first book I knew nothing about planning a novel so I just launched in and typed away until I ran out of steam (around one and a half chapters in). I didn't want to be one of those ghastly people who say, at every social gathering, 'I've got one and a half chapters in my desk drawer but of course I've no time to finish them' so I joined a writing group. One of the first things they taught me was how to make a character chart - by taking 10 or so names, and writing each at the head of a long column in your notebook. If, like me, you're comfortable with spreadsheets, then do it electronically. Then, you start to fill in the columns with names, characteristics, relationship to the others, jobs, and so forth. It's vital that you have this material noted down in order to avoid those awful mistakes, halfway through a novel or maybe in your third, when the blue-eyed boy becomes ...