When analyzing Thread Dumps

Thread States

BLOCKED            Thread state for a thread blocked waiting for a monitor lock.

NEW            Thread state for a thread which has not yet started.

RUNNABLE            Thread state for a runnable thread.

TERMINATED            Thread state for a terminated thread.

TIMED_WAITING            Thread state for a waiting thread with a specified waiting time.

WAITING            Thread state for a waiting thread.

Thread LC
http://bip.weizmann.ac.il/course/prog2/tutorial/essential/threads/lifecycle.html

Tool to analyse thread dumps: TDA

Some good guidelines:
http://nirmalfdo.blogspot.com/2013/05/how-to-find-culprit-when-cpu-starts-to.html