You may use HTML and/or the following tips:
If you write this... You'll get this...
*This is bold.* This is bold.
_This is italic._ This is italic.
+This is underline.+ This is underline.

To start a new paragraph, add a blank line.


This is the second paragraph.

To start a new paragraph, add a blank line.


This is the second paragraph.

h1. This is a big header.


h2. This is a medium header.


h3. This is a small header.

This is a big header.

This is a medium header.

This is a small header.

Numbered list:


# A first item.

# A second item.

# A third item.

Numbered list:


  1. A first item.
  2. A second item.
  3. A third item.

Two levels:


# Fuel could be:

## Coal.

## Gasoline.

# Humans need only:

## Water.

Two levels:


  1. Fuel could be:
    1. Coal.
    2. Gasoline.
  2. Humans need only:
    1. # Water.

Bulleted list:


* A first item.

* A second item.

Bulleted list:


  • A first item.
  • A second item.

Here's a link to "Yahoo":http://www.yahoo.com.

Here's a link to Yahoo.

Here's how we add a picture:

!http://ubersquare.com/waikiki.jpg!

Here's how we add a picture:

Here's how we link a picture to a website:

!http://ubersquare.com/waikiki.jpg!:http://ubersquare.com

Here's how we link a picture to a website: