You need to check three main things:
- Number sequence on the inside page
- The book's binding type
- The publisher
If the numbers go from 10 all the way down to 1 then you've got a first edition.
If it goes from 10 to 2 then you've got a second edition and so on.
Unfortunately these aren't worth as much.
There are three types of binding:
For the book to be a really valuable first edition, the publisher must be Bloomsbury.
- Laminated pictorial boards (not bound in cloth - shiny-ish cover) - only 500 of these printed so very valuable
- Cloth bound with JK's signature in gold on the front - there are 1000s of these because they were published later when publishers knew it would success
- Paperback - millions published so not really worth so much.
So how much money can you make?
- Philosopher's Stone
first edition They are very rare - only 500 were printed
Unsigned they can be worth £3,000 to £4,000
Signed £8,000 to £10,000!
- Chamber of Secrets
Unsigned they can be worth £400 - £600.