All you need to get started as a web developer just like me

Browser
Thanks to browser war, you need lots of different browser to stress test is the website you created is either "what you see is what you get" or the opposite one.

Firefox
Firefox is always my best friend during development process. As an open source project that respect W3C standard, firefox should always be the standard in HTML and CSS rendering.
Get it here: http://www.mozilla.com/en-US/firefox/

Opera
As an alternative browser that have its own loyal community, Opera Mobile Edition has also been well known in latest smart phone. In most cases, pages that display well in Firefox will have no problem in Opera too.
Get it here: http://www.opera.com/download/

Internet Explorer
The long cursed browser by all web developer, be it you happy or not, still monopolize the large naive user group. Most Malaysia, Korean and China users are still using Internet Explorer and do not aware of Firefox. Thus, you still need to test your website on this sucky browser.

Microsoft do not allow you to install more than 2 different version of IE on the same machine. However, there is always a solution from the hacker group.
Get standalone IE from version 3 to 6 here: http://browsers.evolt.org/?ie/32bit/standalone

Wap Browser
Sometime web developers do WAP page as well. And not all developer is rich, like me, i am still using Nokia 3310 that are not WAP enabled.

Firefox WMLbrowser plugin
Simple and nice and integrate into your Firefox browser, a must for all developers that developing dual version of a website with WEB and WAP compatible.
Get it here: http://wmlbrowser.mozdev.org/installation/wmlbrowser.html

Klondike WAP Browser
A standalone browser but is lightweight and accurate.
Get it here: http://www.apachesoftware.com/download_kwpe.html

Text Editor
I prefer to write plain HTML code and CSS code for greater control, rather than those spaghetti code generated from FrontPage. The following editor is what I recommend:

Scintilla and Scite
SciTE is a SCIntilla based Text Editor. Originally built to demonstrate Scintilla, it has grown to be a generally useful editor with facilities for building and running programs. It come with syntax highlighting and utf-8 unicode support (turn on manually), is my best friend no matter what i code.
An installer that includes extensions contributed by Bruce Dodson.

NVU
In case you forgotten how to write fancy html tables with many complicated rowspan and colspan, a WYISWYG tool became handy. NVU as an open source project, respect W3C standard, are able to generate the minimum HTML tag and code for your need.
Get it here: http://www.nvu.com/index.php

CSS
Firefox WebDevelopers Toolbar plugin
I cant develop website without it. It allow you to turn on and off every single function of your browser, such as cookie, css display, images display and so on; Thus, allowing you to stimulate your users browser configuration. (We know there are still freak that refuse to turn cookie and javascript on, or... still browse in text-only browser).
Get it here: https://addons.mozilla.org/firefox/60/

Firefox CSS Viewer plugin
This tool allow you to mouseover any HTML entity and get the rendered CSS result. Very good for debugging CSS directly in your Firefox browser!
Get it here: https://addons.mozilla.org/firefox/2104/

Javascript
Firefox Firebug plugin
A quick overview of FireBug's features:

• JavaScript debugger for stepping through code one line at a time
• Status bar icon shows you when there is an error in a web page
• A console that shows errors from JavaScript and CSS
• Log messages from JavaScript in your web page to the console (bye bye "alert debugging")
• An JavaScript command line (no more "javascript:" in the URL bar)
• Spy on XMLHttpRequest traffic
• Inspect HTML source, computed style, events, layout and the DOM Javascript
  

Get it here: https://addons.mozilla.org/firefox/1843/

Reference
W3Schools.com
Lots and lots of tutorial and reference here layout systematically and are newbie-friendly. It is so good until my University lecturer have to steal contents from here as teaching material. I pointed him out and got a B- for my Internet Computing subject. A lesson I learned here: Don't let anyone stop you from being a great developer, especially those unqualified one.
Go: http://www.w3schools.com

GotAPI.com
This site is super as it crawl all sort of docs from the Internet and put them all under one roof. Highly recommend for all geek.
Go: http://www.gotapi.com/