Michael Hopkins String Pedagogy Notebook
Michael Hopkins website has lots of information, pictures and videos clips on correct technique for violin/viola and cello
James Fiste ~ Cello Professor
James Fiste is Associate Professor of Cello at Central Michigan University in Mt. Pleasant, Michigan. His website contains a wealth of information for cellists. If you are changing from violin to cello this page is very helpful.
The Strad is the premiere publication for violinists, with much information to be found at this link for playing, teaching and practising.