A copy of 'The Perfect Puppy' by Gwen Bailey - essential reading for any puppy owner. You can get it from Amazon or some Pets at Home stores.
Kitchen roll, kitchen roll and erm, more kitchen roll
Shares in a kitchen roll company
Puppy treats for training
A clicker for training if you're going to use one
A tag with your name, address and telephone number on it
A crate or harness for car journeys
Other than that
I use Zoflora disinfectant or Dettol to clean the floors here, you can mix it up in a spray bottle with water to make it handier to use. Biological soap powder is also good for cleaning up puppy wee as the enzymes break down the smell so they don't get attracted back to the same places. Have you got him signed up with a vet yet for a check up and his vaccinations? Many offer puppy socialisation classes which are a must. They can also give you worming tablets and flea and tick treatments.
Other than that you seem pretty sorted, you can always pick up things as you go along as well
