Some resources on task scheduling and CPU utilization

Scheduling Algorithms for Multiprogramming in a Hard-Real-Time Environment: http://citeseer.ist.psu.edu/liu73scheduling.html

Aperiodic Task Scheduling for Real-Time Systems: http://citeseer.ist.psu.edu/sprunt90aperiodic.html

Issues in Real-time System Design:  http://www.eventhelix.com/RealtimeMantra/IssuesInRealtimeSystemDesign.htm

Rate-monotonic analysis keeps real-time systems on schedule: http://www.edn.com/article/CA81193.html

How to calculate CPU utilization: http://www.us.design-reuse.com/articles/article8289.html