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

W3Schools: Links

W3Schools: Images

W3Schools: Image Tag

W3Schools: Address (link) Tag

Notes:

It is not generally necessary to include paragraph (<p></p>) tags as these are generated automatically wherever there is a blank line. Line breaks (<br>) are also automatically generated at the end of a line.

Other HTML may be included (such as <table></table> for tables, <ul></ul> for lists) 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.