Line Breaks
code:
text<br>text
example:
text
text

Paragraphs
code:
<p>text</p>
example:
text

text

Bold Text
code:
<b>text</b>
example:
text

Underlined Text
code:
<u>text</u>
example:
text

Striked Out Text
code:
<s>text</s>
example:
text

Italics Text
code:
<i>text</i>
example:
text

Centered Text
code:
<center>text</center>
example:
text is already centered

Font Size
code:
<font size="1">text</font>
example:
This is size 1 font
This is size 2 font
This is size 3 font
This is size 4 font
This is size 5 font
This is size 6 font
This is size 7 font

Font color
code:
<font color="red">text</font>
example:
red text
You can also use hex codes.
This color is 00a2ff

Font Face
code:
<font face="arial">text</font>
example:
This is arial text
Courier New
Times new Roman
Verdana

Subscript Text/Supscript Text
code:
_text
^text
example:
_Sub text
^Sup text

Links
code:
<a href="http://www.google.com">Google</a>
example:
Google

Adding Images
code:
<img src="picture.jpg">
how does this work?
You need to upload your image to tinypic or photobucket.
The place where it says "Direct Link" under the image.
copy that link!
Paste the link in place of picture.jpg.
There ya go!