I read this book in October 2012, here's a copy of my review from then:
This book is narrated by a single mother, her two boys are Stan who's 9 and 5 year old Kevin. She takes them to the seaside as they've never seen the sea before but they go during the week when they should be at school, arriving late at night when it's dark to stay in a hotel. She takes all her money on the trip (loose change in a tin) and none of the visits to the beach, cafe or funfair go well, as you read the book and it becomes darker you know it won't have a happy ever after ending.
I felt sorry for the three of them, it becomes apparent from the start that the unnamed mother is unwell and suffering from mental health issues. Social workers are mentioned and she tells us how Stan often gets himself and his brother to school in the mornings, and how when they need picking up she does sometimes get there, it's just not at the same time as the other parents.
I don't want to say too much for fear of giving the ending away but although this book is heartbreaking it's a must read. Even now months on from when I read Beside The Sea it has stayed with me and probably more so than any other book I've read.