I initially used InterDev that came with VisualStudio, when I wasn't really familiar with ASP/JavaScript. It has different ways to create scripts (editing the source directly, drag-n-drop), it gives you syntax highlighting to show you where you might have missed a quotation mark or something like that.
Now that I'm pretty well versed, I still use it, but I always edit the source directly. I could use notepad/wordpad and have them save in a plain text format to remove all special characters, but then I wouldn't have the pop-up tips and things that InterDev has. If you have access to it, I highly recommend it.