DS (2.7) is going to become a big brother in a few weeks time (all being well).
We have read him some age appropriate books ('my new baby', the berenstein bears new baby book, and some others which are about babies/new siblings).
He came with me for a growth scan last week, as I didn't have any child care, so has seen baby sister on the monitor.
He is now going on and on about baby sister being on the computer, and we were telling him yesterday that mummy will go to the hospital to have baby sister, and his grandad ('deda') will be coming over to visit on a plane. (FIL will be flying in just before my due date, and is staying for a week).
Now DS is convinced his sister is arriving by plane 
I have got him a wee present from his sister, and he will get her a wee something once I start mat leave.
He has felt her kick (a lot - they are fighting already!!), and is always touching my bump and talking to his baby sister.
Nursery have done some baby stuff, as he is not the only one in his group to be welcoming a sibling this year - so they have been playing with dollies, and talking about babies crying and needing milk etc etc (it helps that one member of staff in his room is due just after me, so he is surrounded by bumps!)
So this seems like a lot of preparation, and I'm hoping it pays off. but the reason I ask, is my parents were laughing at me yesterday, as they said they did nothing to prepare me for the arrival of my sister, and I always resented her (it's true, and I still do to some extent). They just presented me with a new sister one day, and that was that. They keep on and on about how DS will hate his sister and will spend the next 30 years of his life plotting ways to be rid of her, and tormenting her at every opportunity. They think I am being ridiculous, and that all eldest children hate younger siblings, and it's normal.
DH thinks I am massively overthinking it all, but he and his wee brother get on really well, so he doesn't really get the dynamic in my family. and he has no idea what, if anything, his family did to prepare him for the new baby.
So I am just wondering what other people did, and what worked best for you/what was not worth it?
(I have read 'siblings without rivalry', and will re-read it before baby arrives, but anecdotes are more than welcome!!)