These two books are very good for learning Scheme seriously:
Please don’t bother reading them if you simply want to use GNU Artanis to build your web application/site in few minutes.
And if you really want to try to work these books seriously, please ignore GNU Artanis before you are done with them.
But once you’re done reading them carefully, you may want to write a new GNU Artanis all by yourself!
Hold your horses. ;-)