There's this really old Garfield poster that says something like: "The material things in life aren't important to me, but I do like the stuff".
I collect things I like. When I was young, I used to collect tiny shards of ceramic tile from building sites. I used to collect the liners from soft drink bottles, when they had promotional copy on them. For a while, I used to collect badges and pins. Old coins. Stamps. But as you grow older, your collections change, become more sophisticated, somehow. You grow bored with bottle liners and become interested in books and records. Things you can only have by exchanging money for them. You turn away from being a mere collector to being a completist. This is dangerous territory; a land inhabited by madmen, human squirrels, anoraks, artefact smugglers. Passionate folk, understandably, but quite, quite insane.
Wouldn't we all like to own first edition, signed copies of things like Memoirs of a Geisha by Arthur Golden (worth about £600 mint condition) or George Orwell's Nineteen Eighty-Four (worth about £4500 mint condition) or even Bram Stoker's Dracula (about £20000 mint condition)? Frankly, possessing such treasures would give me a nervous breakdown (is there too much humidity in the room? the dust jackets must be protected from fading by sunlight! are they insured? no, don't touch those!). So therefore I do not collect rare and valuable books - we'll conveniently forget about the affordability of the price tags and my current state of solvency. Most of my small collection of books is comprised of paperbacks. I like these immensely: they're easier to hold whilst reading, are cheaper and stack well on the shelf. Also, there's none of the fuss about whether it's a true first edition and all that nonsense.
For those of you who are interested in whether a book will be worth anything, here are some handy hints. A true first edition is actually the first edition, first print of a book. Second and third printings may look identical, but will be worth less because they do not represent the original state of the book. Check the publishing history page of the book: most books from the latter part of the 20th century onwards have a strike through line. It's the line of numbers that usually looks something like this: 2 4 6 8 10 9 7 5 3 1 . The lowest number you can see is the number of the print run. The paperback copies of Labyrinth by Kate Mosse in the shop at the moment have a strike through line that reads 15 17 19 20 18 16 14 . These copies are from the fourteenth print of the paperback. Sometimes there'll be a single number, as in Paulo Coelho's The Alchemist: 44 . The instant you walk out of a bookshop with a paperback, it's worth much less. This is because you've turned it into a second hand book by buying it and there are a million others like it.
Hardcovers may sometimes appreciate in value the longer you keep them, but not all hardcovers. The trick comes in knowing which ones will become valuable. If it says New York Times Bestseller on the front, it's not a first edition. Debut novels by authors who will eventually become famous are usually valuable to collectors. Acclaim adds value as much as does exclusivity. Often these will have very small initial print runs, the publishers being cautious with new talent. Harry Potter and the Philosopher's Stone (500 copy first print run) versus Harry Potter and the Half-Blood Prince (10.8 million copy first print run) is a very good example. Bet you wish you hadn't waited for Smith's White Teeth or Mitchell's Ghostwritten to come out on paperback, now don't you! In reality it is nearly impossible to know intuitively whether a debut novelist will make it big later on.
I collect things I like. I listen to the records I buy and I read the books I buy (or plan to read, at least!). I'd feel too sorry for a really precious hardcover to even open it. Paperbacks come in wonderfully designed covers, especially when they form part of a series. I've discovered many awesome books and authors by collecting other titles in a series: the essential.penguin series of the late '90s comes to mind. I wouldn't have known about the joys of Carson McCullers without it. Admit it now: how many of you were first drawn to the books of David Mitchell by the amazingly well designed covers? In some cases you can judge a book by its cover - moreover, a book can be judged by its publisher. Good publishers and theirs editors can throw money into making their products look good. Certain kinds of books are targeted to a certain audience by how they look. If you want to stay away from mass market fiction, don't read books where the name of the author is printed bigger than that of the book, or those that have the name of the author in giant embossed gold lettering. Et cetera, et cetera.
In the end, a collection of anything is only worth something if it has been assembled with love and passion, and yes, maybe even a touch of madness. It should be amassed by the collector for the collector, not to impress friends or according to some fashion. A good collection will reflect the compulsions of its custodian. A good collection is the most sincere self-portrait anybody could make.