We also read 'there's a house inside my mummy', but only a few times (it was the way we told him I was expecting!), but I thought it was quite good as it talks about pregnant mummy being tired :-)
Re: the inevitable jealous. I'm not sure it is inevitable. DS1 was 3.9 yrs when DS2 came along last May and it's went so much more seamless than I thought. I was expecting lots of resentment and 'send the baby back' comments. But to be honest, the only time he said anything like this (he told me that he shoudl have said 'no' to another baby when we told him earlier...) was when DH spoke without thinking and said there was no room in our bed for DS1 because the baby was there... (as soon as it was out of his mouth he knew he'd messed up as DS1 ran away upset). But that was entirely our fault, and it's the only time he's mentioned not having DS2 in the house.
We told DS1 when I was 5 months pregnant and we didn't go on about it much after that (we didn't want to keep banging on about it) but every now and then DS1 would make comments like 'the baby can use my old high chair when it comes as I sit on a big chair now', 'the baby can have these old wellies as I have new ones', 'the baby can sleep in my bed... (to be fair we did kaibosh that idea pretty quick!).
We always presented the baby as his baby brother/sister throughout my pregnancy (e.g. mummy wasn't having a baby - he was getting a baby brother or sister) so when the baby arrived he felt a lot of 'ownership' and couldn't wait to show the baby off at playgroup (where he lapped up all the comments about DS2 being lovely, saying 'he's my baby brother').
I also made a rule that when the baby napped, I'd play with him so that he could still have 1:1 time. It has meant our house has been a tip for days years but I notice a big difference in DS1's behaviour on days when DS2 naps well and we get lots of uninterrupted playtime.
DS1 does get peed off with me and DH when we can't play with him (because one of us has to make tea while the other looks after the baby) but he never takes this out on DS2, it is always me and DH that are the subject of his wrath.
I think the personality of your child is key though, Since finding out what a sister/brother was when he was just over 2 years old, DS1 was always keen on having a sibling (as most of his friends have a brother or sister), and he loves the idea of being 'a big brother'. So we've not had many issues with him, and he offered (with no prompting from us) to give DS2 his old baby toys and clothes (he looked through them all with us).
My friends daughter was a tad younger than dS1 when she had a sibling and she was the complete opposite, refused to let her new brother have any of her old toys and played up the whole time to get her mums attention, but a year on and she was accepting of him (if annoyed that he was always trying to spoil her games!)
Oh, and we got DS1 a big box of lego 'from DS2' when dS2 was born and that helped loads 
. Getting family to bring a wee thing for your eldest when bringing stuff for the baby is well worth it for making him feeling included.