Sleep Study for 20 month old.

Hi lovely ladies.
I was just wondering if anyone else has taken their child for a sleep study for snoring and/or sleep apnoea as a toddler. My son snores and has sleep apnoea and his doctors are thinking that his adenoids and tonsils are causing the problems. We have to go for a sleep study in the next couple of months (waiting for a phone call with an appointment day/time). I was just wondering if other mums who have taken their children could give me a little insight into what to expect and how to get him ready. Thanks