Today we spent ages searching for the first Harry Potter book because one of the kids wants to start the series again. We kept finding the second one or the fifth one but not the first.
So Abbie says as she's going to bed, "Mum, I'm reading the first book - it's called 'Dig, Dig Digging' and then the second book is called 'P. B. Bear'". They are both stand alone picture books.
I think we must discuss books that are in series quite a lot. 'Which one are you up to?', 'Is it different to the second one?', 'I liked the fifth one the best' etc., etc.!
btw 'Dig, Dig, Digging' is a great book especially if you have a preschooler boy who loves cars/trucks/buses.