You can make money online by buying and selling first edition books
A gratuitous plug for Garry O'Connor's new book 'Chaucer's Triumph'. Why am I plugging it? Because it is a self-published book with a necessarily short print-run, but it has got some interesting fans, including Sir Derek Jacobi and Garry O'Connor has just been on Radio 4 and may well appear in other media forums to talk about his book and also self-publishing in general. I am a book collector myself so I advise you if you want to buy the book, to make sure you get the First Print of the First Edition, signed by Mr O'Connor if at all possible.
I shall at some point be creating a blog about collecting first editions.
If you want to buy it do me a favour and get it through this link ! The Central Line