--First let me start by saying that if not all of this information came from w3schools.com, THANK YOU!  That my information is indicated by the --.  I wouldn't really call this a cheat sheet per say, just think of it as someone taking notes for you in school.  I do encourage people to go learn HTML and then refer back to this as a reminder sheet. The best way that I can describe HTML to you is if you think of it as a foreign language, morse code, and english all in one. That you are putting together a message to give the web browser. Confused???  Here is what w3 says it is:

What is HTML?

HTML is a language for describing web pages.

    * HTML stands for Hyper Text Markup Language
    * HTML is not a programming language, it is a markup language
    * A markup language is a set of markup tags
    * HTML uses markup tags to describe web pages 

What are HTML markup Tags?

HTML markup tags are usually called HTML tags

    * HTML tags are keywords surrounded by angle brackets like <html>
    * HTML tags normally come in pairs like <b> and </b>
    * The first tag in a pair is the start tag, the second tag is the end tag
    *

      Start and end tags are also called opening tags and closing tags.

The purpose of a web browser (like Internet Explorer or Firefox) is to read HTML documents and display them as web pages. The browser does not display the HTML tags, but uses the tags to interpret the content of the page.  

--Okay, remember the morse code, foreign language, english stuff, is it starting to make sense now? NO! Okay keep reading.

--These are HTML markup tags as they would appear on a web page editor or how you would set them up in notepad (windows) or nedit (linux):

<html>
<body>

<h1>My First Heading</h1>

<p>My first paragraph</p>

</body>
</html>

--Now I am going to pick on just the first three because hopefully the rest well be easier to understand after that.

<html>   --You start your page with html so the browser knows in what language you are describing so it can display using that format.
<body>   --This is where you will begin to build your page, for right now just remember that.

<h1>My First Heading</h1>   --This is pretty self explanatory, but I will explain.  First, you see <h1>.
			    Well, simply put "heading one." Thus "My First Heading." Now you want to know about </h1>, again self-explanatory. Think
			    of this symbol "/" as a stop sign.  Here is where the foreign language, morse code, english comes in:
--you: "browser"
--browser "yes"
--you:"do you speak html?" <html> foreign language 
--browser "yes"

--you: "browser start loading body." <body>  Easiest way to explain you have a person and you are going to put clothes on them. which means you are going to be using colors, images, and so forth, which coincidentally is your background.  For the guys and girls, the body is a chick, she just put on clothes, and everything else that follows is make-up, perfume, jewelry : ) 
--browser "ok"
--you: "browser my heading starts here and stops here." open<start h1 >next My First Heading<next /stop h1>close (make-up starts here)

--all of these symbols "</>"  and others, are morse code for the computer telling it where to start, stop, open, close, and other things. The most important thing to remember is that when you start something you must remember to stop it or it will not display properly. <h1>start </h1>stop *do not type start or stop* You have up to six headings on a web page, atleast thats what they teach you. <h1> through <h6>.
--all of the letters are like an abbreviation to a word h1=heading1, the lower case letters are also called tags to be politically correct. My suggestion get a list of all the "tags" you use in html, with the full name, and with a definition next to them, so you know what they are. This is very important because I can't cover them all and if you use them wrong your page will look funny.
--as for the english, well you can read this right?  So now you should be able to speak a foregin language, do morse code, and write in english : )
--if you are still having trouble understanding this then my advice go learn html at w3schools.com, they have examples you can try if you can't visualize what I am talking about : )

<p>My first paragraph</p>--So test your knowledge at this point, try to translate this into a english sentence. The answer is on the back if you can't figure it out : ) 

</body>--remember what you start you must stop
</html>--end of conversation : )

--By now you hopefully know what HTML is, how it should look before you add things when you use an edit application, and what everything stands for. This to me is about as basic as I can get HTML to a point that I understand.  Of course what you really want to know is what is all that other stuff that you see oh say when you copy and paste a html script and put it into your myspace page to make all those pretty little images : ) Oh and where does it all go on the page.  Thats where I have to say go learn the more in depth stuff for now this should just get you started or just be a reminder.

*MsJeeves*