We took our daughter for her Birthday treat as we are huge Harry Potter fans. You have to book a tour and tickets, £28 each, on the internet booking site, you can't just turn up on the day and get a ticket. Don't bother paying extra for a digital guide for £5. Although they are very good, you are so busy looking at every thing and taking things in, you forget to turn it on so it's a waste of money. It's very well organised in that you have a specific time for your tour and enter the building as a large group, however once inside it's so large and there's so much room, you can see every thing, take as many photos as you like and take as much time as you want to go round. The sets from the film are absolutely amazing, we took over 200 photos all together. The model of Hogwarts Castle is so detailed it was fantastic. There is a cafe on site in the foyer and half way around the tour there is a sit down area with a small cafe where you can try butterbeer which is like American Cream Soda but thicker and creamier, it was lovely but pricey at £2.95 a small glass! There's a large gift shop selling everything to do with Harry Potter and you can easily spend and hour just in there alone! It's very accessible for everyone and a brilliant day out.
Further reading: Taking a grandchild to enjoy the Magic of Harry Potter Studio Tour