well there are a couple of editors that you can use like:
I will be using notepad++
HTML/XHTML/HTML5 have different Doctype Definitions (DTD’s) to be identified by browsers. For standards compliant HTML a web page needs a valid DTD (at the top of the html page). HTML 4.01 strict DTD :
<!--DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
For information on valid DTD’s, see http://www.w3.org/QA/2002/04/valid-dtd-list.html.
(example: <tag> signifies the begenning of an element’s section and a closing tag (example: </tag> is signifies the end of an element’s section. Here’s an example of a how a paragraph element tag would be used:
<p>Welcome to my webpage</p>
For some tags, the element does not need to surround or encompass any content. In those cases, it is not necessary to have both an opening and closing tag. Instead, a shorthand is available to close out the tag. It consists only of a forward slash and a closing angle bracket. An example of it’s usage can be seen in image element tag:<img src=”my_image.jpg” />