Here's how it works:

1. you list the books that you want to give away.

2. 10 listings give you 1 point.

3. you use that point to mooch a free book.

you can check out the books I've put up for adoption here:

http://www.bookmooch.com/inventory/alphalim

note: I just cleared my bookshelves, so these are books I want to give
away because they're no longer relevant to me, or I found duplicates.

these are not necessarily books that I recommend ;).

to read more about BookMooch:

http://www.bookmooch.com/about/overview