Some basic HTML tags:
Italic:
<i>italic text</i>
Bold:
<b>bold text</b>
Quoted text:
<blockquote>quoted text</blockquote>
Image:
<img src="http://www.somewebsite.com/photo.jpg">
Link:
<a href="http://www.somewebsite.com">link to a website<a>
Link, opens in new window
<a href="http://www.somewebsite.com" target="_blank">link to a website<a/>
To separate a "teaser" intro from the body of a long post, use the special "break" comment/command:
<!--break-->
Some basic HTML tutorials:
W3Schools: Formatting [1]
W3Schools: Links [2]
W3Schools: Images [3]
W3Schools: Image Tag [4]
W3Schools: Address (link) Tag [5]
Notes:
It is not generally necessary to include paragraph tags as these are generated automatically wherever there is a blank line. Line breaks are also automatically generated at the end of a line.
Other HTML may be included (such as <table> for tables) but some tags are automatically stripped by the software for a variety of reasons. You can use "preview" to verify whether your tags are allowed.