Here is a link to the best instructions I've found (and they have pictures AND they're easy to make!!!)
http://imageevent.com/bizylizy/craftsguineapigfun/lilygraceshowtomakeacozy?n=0&z=1&c=1&x=1&m=9&w=0&p =0
I have made two of them, and still have lots of fabric left over from my two remnants (one fabric, one fleece). There are also lots of other cool ideas there, along with many different projects you can make, including a tunnel and a hammock. Good luck, and don't forget to take pig-tures! =)