Charlie and the Big Birthday Bash by Hilary McKay
Charlie can't believe his big brother Max hates parties and doesn't want to celebrate his birthday. So Charlie sets out to give him a surprise birthday bash that he'll never forget. This is the eighth book in this hilarious series, which also includes: "Charlie and the Cat Flap", "Charlie and the Great Escape", "Charlie and the Big Snow", "Charlie and the Rocket Boy", "Charlie and the Cheese and Onion Crisps", "Charlie and the Haunted Tent", and, "Charlie and the Tooth Fairy".