Encyclopedias & handbooks are a good source of definitions and overview articles. We still have LOTS of great reference resources in PRINT (!) in Cornell's Reference Collection on the main floor of the library. But here are a few online resources to get you started:
From Swarthmore's Engineering Department's page:
"As seniors, students complete a yearlong design project that provides an opportunity to integrate and build upon what they have learned in their coursework. Recent projects include autonomous operation of an elevator by a robot, building a wireless sensor network, developing adaptive noise-cancellation techniques, building fuel cells and hybrid electric vehicles, and designing a constructed wetland to reduce pollution in stormwater runoff. "