Rocket Ship Galileo

Someone asked me to sell a book for them on ebay (Rocket Ship Galileo by Robert A. Heinlein), and is a first edition. I do not know if it's as good as they think, though, because I suspect that this is not the first impression, and a library binding. I'm not in the old books (yet!) So any help on where to find info on this book would be much appreciated!

You can at least see what the rest of the market is the sale of the book by going to the well-known used-book stores on the Internet, such as:
http://www.abebooks.com/
http://www.alibris.com/
http://www.powell.com/
Search these sites for books with similar binding and the date of printing. I know that independent bookstores Abebooks use as a showcase for their books, they are probably just because the prices are the sellers in the company.

These people have new, used and printed books. If they do not what you are looking for, they will find it for you and contact you when they have. Then you can buy by credit card and they ship to you.
http://www.powells.com/
Hope