Some useful MRI and histology links:

Histology World
Biology Glossary
MRI Glossary
The basics of MRI
MRI Tutor
MRI Safety
An excellent Introduction to Quantitative T2 MRI as a pdf or paperback
AnalyzeNNLS (opensource software written by Dr. Thor Bjarnason)

Blogs and books by people living with and affected by MS:

My New Normals
MS Connection Blog
Someone like me – an online community for youth affected by MS
Black Patent Shoes – Dancing with MS