I would lean towards the toddler book. I think long term your money would be better spend on that one and maybe see if you library had the baby one. I have the toddler one and it is quite clear, must read it again for this 2nd bub. OH don't forget your local ABA may have a copy to borrow. Also have a look at Elizabeth Pantely's website, she has some downloads for working out bedtime routines etc (well she did last I looked, hope they are still there)

When I was looking for sleep help with DD1 I did a lot of reading on various forums to see what others were doing. A lot of parents were recommending the toddler book, it was written after the baby one, so it a lot clearer and easier to follow. Problems with the baby one were ironed out with the toddler one. (gee hope I made sense)