Awww! What beautiful kittens. They're the most popular colour too.
However be prepared to:
Go to the toilet whenever you have the chance, even if you don't need to go because the kittens will come for a cuddle and a snooze just as your bladder sends its FULL message
Wear jeans at all times (see the next one)
Develop the ability to walk like a cowboy in a 1950's western. That bow-legged stance will be needed because the kittens will climb up your legs, especially at feeding time. This will hurt unless you're wearing jeans.
Be awoken by kittens bouncing on your head at 5am. They're most active at dawn and dusk. Although they also seem to tune into dawn and dusk in other parts of the globe.
Develop your cat language skills. You can learn from Mum as she'll start off with the simplest sounds ("it's ok, Mummy's home") and gradually become more complex.
Spend 13 weeks of your life with four little fluffballs who'll steal your heart and that you'll always remember.
Cry when they go to their new homes but know that they'll always remember the love and care you gave them.
Please have Mum and Dad neutered as things could get out of hand if you don't. Plus you don't want to go through all the cost, effort and pain of saying goodbye again! The GCCF (the biggest UK organisation that registers pedigrees) require members to keep the kittens until they're 13 weeks old, before they're allowed to go to their new homes. Studies have shown that kittens need this old in order to have the best chance of coping well with the drastic change. It also means that the kitten is vaccinated before they go to a new home, reducing the chances of them getting something nasty.
Enjoy 