For the time being, you can develop and test on your local file system. You don't need a web server and it's in fact much faster without one since the browser will load files directly. I just drag and drop my main index file over to the browser and refresh it whenever I make changes.
For a hobby project I'm working on, I'm testing development with Visual Studio 2012. I was going to post my thoughts about it after I was done, but for the time being I think it's something you may want to consider. I used notepad++ previously and it's still fairly good in its own way, but the intellisense in Visual Studio is a nice addition. It's not perfect, in fact none of the IDEs are (I also tried Netbeans at one point), but it's good enough so long as your objects are strongly typed. About the only thing I am mad about in VS 2012 is that Microsoft didn't bother writing plug-ins to debug via Firefox or Chrome browsers. I hate, I mean absolutely HATE using Firebug over Visual Studio's debugger, but it's an unfortunate reality. Eclipse does work well with Firefox (and I believe Chrome) and that is another option, although the JS intellisense is rather poor and Eclipse sucks system resources like a sponge in water.
I know nothing about web development
Honestly, keep it that way. The less you know about HTML and CSS, the better. Those two should have died a long time ago, but the powers that be want them to stay and live on. They are not meant for writing games and apps, they're meant for displaying pages of data. If you have the time, render your UI via the Canvas, just like you would normally do in a native game. It's worth the effort. Don't be fooled by JQuery UI either. It relies heavily on HTML DOM to layout the controls, and that's where the problem is.