First edition , first printing books are more sought after as they are the first printing available and become less available as time goes by.

Hardcover books are worth much more than paperbacks to a collector.

If you open your book to the copyright you will find a numberline if your numberline starts or ends in a one it is a first edition such as 123456789

You might find the numberline to go backwards such as 987654321 this is also a First Edition.

There is another way which you might find it FIRST EDITION or FIRST PRINTING may be writen out and beneath it the numerline starting with 234567589.

If you do not see the First Edition written and your numberline looks like 23456789 you have a 2nd edition and so forth. you might even see up into the 100's in the numberline.

I hope this helps the next time you are looking for a first edition book.