so that no one else can claim it?

If it's a WL book you can go to their WL and post it directly to them from their own list. Just make sure you know who's WL you're on.

If it's a book already in the system and you're not worried about it being snatched up very quickly, post it to your shelf and have them go to your shelf an order it from you. If there are already a few in the system, the site will order those books first, so you should have some time.

If it's not WL'd, you can put it on your Reminder List and it should show how many are in the system so you can tell.

If it's available in the system (including if your copy is the only copy), there's also the "mail it to a friend" option.  After you've posted it, go to the book description page and the option will be in the upper right under "Your book is posted".

The "Mail to a friend" option is different.  It does not involve credits.  (Great for freebies on deals where you want a book to keep it's footprint.)  But it also requires us to type in the address.  I think it also requires us to mark the book received. 

Also, only non WL books can be sent that way.

That about covers it Michelle    You will want to know 1) if the book is wishlisted, and 2) if you wish to receive a credit (or not).  Then choose one of the options suggested above. 

Using the 'friend' option tracks the transaction, no credits transfer, and sender marks the book received (so communication is required).  Only works for non-wishlisted books.

Posting to your friends wishlist will transfer a credit and the system tracks the transaction  (be careful to post directly from her wishlist not the book information page, and make sure the pop-up window states the name of receiving member).

If the book is already on your bookshelf (or isn't wishlisted & can be posted there) your friend can order it directly from your shelf.  A credit transfers with this type of transaction also.