Here is a listing of resources and websites that I've found particularly useful. Some of these are so helpful they get visited on a daily basis. I will update this list periodically as additional websites are found for easy reference.

I've been asked several times now about some of the reference books that I use on a regular basis, so I thought it might be useful to post a listing for future reference. 

For those considering a career path in Mechanical Design, Analysis and Test for Electronics Systems development in the broad range of fields including avionics, aerospace, alternative energy, commercial electronics, communications, industrial electronics, medical devices, network systems and transportation - as well as good references for Systems and Electrical engineering types that desire to broaden their understanding (particularly the Thermal Management and Product Reliability references). 

I have found these to be an excellent core reference set (by topic):

Design

Statics and Dynamic Loading

Thermal Management

Product Reliability

Electromagnetics (EMI/EMC)

General Reference