Well in the beginning I typically purchase the companion guide that is produced. I haven't purchansed other books. I do read alot of tech articles and community posts that help out. Below is just one link to a collection of SMS/SCCM books. Many of the scripts that worked for SMS 2003 will continue to function in SCCM.
http://faqshop.com/books/smsbooks.htm
System Center Configuration Manager 2007 Administrator's Companion
Mastering System Center Configuration Manager 2007 R2
System Center Configuration Manager (SCCM) 2007 Unleashed
System Center Configuration Manager 2007 R3 Complete
