Once it was a niche for bookworms, or the seriously rich willing to pore over dusty tomes in an antiquarian bookshop. Now anybody with access to the internet or spare cash on the high street is able to become a literary collector.

Targeted book-buying is becoming one of Britain's favourite hobbies, with thousands changing hands for rare first editions and record queues at meet-the-author events to secure a signed copy. Some appear to regard books as a sound addition to an investment portfolio that might already include antiques, coins, stamps or wine, while others are merely content to seek a memento or a special gift.

'It's quite staggering, the number of customers who are new to collecting books,' said Justin Phillips, a specialist at Bloomsbury Auctions in central London. 'It is one of the boom markets and has become a mainstream phenomenon.

'We have a small percentage of customers who collect for an investment. There's an increase in people buying up a complete collection over a number of years. The value of Winnie the Pooh first editions with dust jackets has doubled over three years.'

Good condition first editions of Harry Potter and The Philosopher's Stone or The Lord of the Rings can fetch £25,000. The trade in rare books has been fuelled by eBay, and the growth of reading groups, literary festivals and in-store events.

Stephen Poole, manager of Biblion, a book dealer in central London, said: 'A lot of people are buying first editions as an investment. People are now nervous of stocks and shares, whereas books are like an extension of antiques and paintings. It's possible to do extremely well.'

The trend of 'public collecting' has now arrived squarely in the high street in the form of limited editions, a money-spinning concept introduced by Waterstone's in tandem with several publishers. The limited editions are numbered and signed by the authors, come in a slip case and have a print run of around 1,000 to ensure their rarity. The 'must-have' books are more expensive than the regular editions, which continue to be on sale elsewhere in the store.

A forthcoming limited edition of Status Quo's autobiography XS All Areas will be bound in denim with a DVD attached and cost £40. Other limited edition titles include Yann Martel's Life of Pi, costing £25, which Waterstone's estimates will be worth a collector's price of £50-£75.

But Peter Selley of Sotheby's urged caution: 'Collectors would always prefer the first edition of a work rather than a limited one that came out some time later. They're lovely to have, but they're not dead certs as investments. There were some books that had a run of 1,000 copies in 1890 and you still see two or three of them a year, so they couldn't be described as rare.'

Jason Butler of Bloomsbury Financial Planning advised collectors to take a balanced approach: 'Only invest in rare books if it's a personal interest. Like stamp-collecting or wine, you do it because you have an interest and knowledge, and making money should be the last point. Anything you can touch and feel and enjoy is always a good investment.'