There are currently no new study guides published for the SP series. So this means you have to build it yourself for a study guide. You would start with the specialist exam objectives that are posted on the education site. Every topic listed here would have to be found in the existing material. This is your study guide outline. You must know this material to pass.
Test Topical Outline
http://www.juniper.net/us/en/training/certification/resources_jncissp.html
Original Study Guides
The original M series study guides are posted as pdf downloads on the Juniper site. These are still valid for the topics that they cover. But obviously newer features are not here.
http://www.juniper.net/us/en/training/certification/books.html
Day One Series Books
The Day One series books in the Fundamentals series will give an organized print view of these topics for study. The ones on MPLS, automation and ipv6 should be applicable to the SP track.
http://www.juniper.net/us/en/community/junos/training-certification/day-one/
Support Documentation
You should also check the main support menu and then drill into the equipment specific menu on the left to see the getting started guides and documentation.
https://www.juniper.net/customers/support/
Courseware Store
If you have a budget, the books and lab guides for the public classes are availabe to purchase for self-study at the coursware store. The JNCIP-SP education page lists these classes as covering the applicable material. The exams are built from the content of these courses.
http://www.onfulfillment.com/JuniperTrainingPublic/WelcomePublic.aspx?sid=323
JNCIS-SP courses
Junos Intermediate Routing
Junos Service Provider Switching
Junos MPLS and VPNs