Hi Picky,
I had my tonsils out 6 years ago when I was 21, having suffered 5 years of tonsiitis following Glandular Fever when i was 16. I stayed in hospital for one night only, and they put me on the ward with the older ladies not the kids. The first 24 hours I was pretty much out of it on painkillers in the hospital (i was in so much pain they gave me morphine and i was tripping out), and then I spent 2 days with incredible sore muscles as a reaction to the general anaesthetic. I remember 3 or 4 days of lying on the sofa drooling uncontrollably, so invest in some big hankies!
Make sure you have codeine and some sort of throat spray as it will be sore, and drink lots and lots of water. They'll tell you not to drink anything coloured so that if (when) you're sick you'll be able to see if there's blood in it (nice). I remember eating being unconfortable but I managed a dominos pizza at the end of the first week, so not the end of the world. Scratchy things help with the wound recovery apparently.
I hardly ever get sore throats now so its totally worth it, but you can get phantom tonsil pain sometimes, which is odd. Expect to be out of action for about a week, and get someone else to look after the kids. Best of luck, hope it goes ok x