I want to learn javascript in more detail, any advice?

[PeteTheELite]

I have recently learned html, some css and a bit of javascript in computing at school. But I wish to do computer science at uni so I would like to get a bit of a headstart in the coding world. So can anyone recommend some good tutorials, sites for someone wishing to learn javascript at a beginners level. I have so far done some basic stuff like make calculators, making basic arrays, using variables, if, for, while statements, using functions, using forms, using frames but it is all only basic stuff. So Im probably at just past beginner stage and want to get onto some real learning. So any sites/advice/info would be greatly appreciated. Thanks!