Links

Some interesting links concerning garbage collection

Know how about java gc

Sun's memory management white paper lots of background knowledge but only up to java 1.5
Javaworld article rather old but generations well explained
list of articles on 'stackoverflow.com'

JVM options

tagtraum industries list of vm flags The initial developer of GCViewer collected quite a few vm options (up to java 1.5)
Alexey Ragozin's blog JVM garbage collection options cheat sheet very clearly laid out (including G1 options)

(other) Tools

IBM's Garbage Collection and Memory Visualizer very powerful analyser - doesn't support G1 log files yet (as of 01/21/2012)