Techie stuff/moving on

Here's one of the techie things that I want to be able to do - not to have a white sky when focusing on something in the foreground. On this occasion I was so taken up by the combination of new camera (courtesy of my mother-in-law - thanks so much, Barbara!) and of my son deciding that the shot would be improved by his presence that I couldn't even think about what the background would look like. The thing is, numbers just escape me. If dyscalculia had been invented when I was at school I would have had it, in spades. I still remember the look of horror on my mother's face (she was a primary school teacher) when I told her that my IQ test had been easy and that I'd 'just' missed out all the questions with numbers. She obviously saw a future for me that consisted of sitting at the back of the class with raffia (any other British readers remember Thora Hird in 'Pat and Margaret'?). But I need to get to grips with numbers to do what I want with my camera. As always, I turn to a book for help. At the moment I'm thinking of getting 'Digital Photography for Dummies'. Any other suggestions?
When this photo was taken in early May it didn't seem all that poignant to me. The school chamber choir had just reprised their 'Jephte' at choral evensong in Dunfermline Abbey. Now, I realise that my son is about to leave behind all things to do with school, including school uniform. With a few days left of school, and that newfangled invention of 'study leave' having morphed into a few weeks of limbo before the end of term, the sight of him in uniform already belongs to the past.