The British Judo Association have launched a site to help Judoka with the technical grading syllabus with photographic sequences to show the techniques and some textual description alongside.
http://www.britishjudoeducation.org.uk/
Ask your coach for input on techniques, don't try to learn them purely from books/online videos. Practice lots.
Don't forget the syllabus is the minimum required for grading, your coach may have other requirements too!