Well like any language, it has some strengths and some weaknesses, so it depends what you want it for. Javascript is a very forgiving language; it is weakly typed, involves no memory management, and because it is a scripting language, it can be tested and debugged very easily without having to compile anything. It is also object-oriented, and shares a similar syntax to important compiled languages such as C++, Java and Actionscript. However, it has some downsides as well. It is quite slow compared to compiled languages, its only real use is in browser scripting, it is clientside-only, and in order to make anything of it you have to know at least some basic HTML and CSS. However it sounds like you have this last requirement under your belt already, which is good. As a development environment for Javascript, I write my code in Wordpad and use Firefox (with the Firebug extension installed) for testing, and that works pretty well for me.
So basically, go for Javascript if you want a shallow, leisurely learning curve and don't mind not having access to supreme speed and power. Also, even with all the limitations Javascript has in speed and scope of capability, it does have something special that none of the compiled languages have: eval(), a godlike function that makes your life so sickeningly easy, many 'proper' programmers refuse to use it at all, on the basis that doing so is a bad habit, a sign of weakness, or even downright cheating.