Web Links
The Designers Guide
http://www.designers-guide.com/
Much useful information on analog simulation including source code and reference material for the VBIC BJT model. Edited by Kenneth Kundert who is the original developer of the Sparse matrix solver used at the heart of all SPICE3 based simulators including SIMetrix.
Designing Analog Chips by Hans Camenzind
http://www.arraydesign.com/downloads/index.html
Book available for free download. As well as being a good introductory course to designing analog ICs, this book is also an entertaining read even for experienced designers.
AboutSPICE
http://www.aboutspice.com/
Vendor independent source for SPICE simulation.
BSIM3/4 Official Web Site
http://www-device.eecs.berkeley.edu/~bsim3/
Source code and documentation for BSIM3 and 4
Philips Compact Models
http://www.semiconductors.philips.com/Philips_Models/
Source code and documentation for MOS9, MOS11 and MEXTRAM