These are some of the most useful pages I found for understanding and teaching fMRI.
Robarts Centre for Functional and Magnetic Mapping site at Western
Contains Standard Operating Procedures (SOPs)
The fMRI course at Duke has some great slides available online, many of which come from Huettel, Song & McCarthy.
The Oxford FMRIB group has an intro to fMRI for lay people
MR Physics and fMRI methods
A great, compehensive overview unpacking many aspects of MR physics, including some material on BOLD and fMRI can be found on Questions and Answers in MRI
Douglas Noll’s Primer on MRI and Functional MRI
For a more advanced tutorial, see: Joseph Hornak’s Web Tutorial: The Basics of MRI
Marty Sereno's Movies of Cortical Unfolding, Flattening, and Activity
MRC-CBU Cambridge site has a lot of info on SPM but much is of general interest
An old GE safety video has cheesy acting but powerful demos of the magnetic field (See esp time = 5:18 to 8:45)
MGH has some general information on magnet safety
Neurosynth is an excellent resource that provides a meta-analysis of fMRI studies that is useful for examining activation for specific tasks
Brain Tutor is free software for learning anatomy (particularly cortical anatomy)