If you want to include photos, use BBcode. It takes a little to learn but works on tags just like HTML (opening and closing tags) I believe the tag for image is IMG but please consult the help for the board. Here is a dump from wiki on the subject (I turned off BBcode for this post so that it can be shown). The one you want for graphics is:
[img]http://upload.wikimedia.org/wikipedia/commons/thumb/7/7c/Go-home.svg/100px-Go-home.svg.png[/img]
BBCode example HTML Effect
[b]bolded text[/b] <b>bolded text</b>, <strong>bolded text</strong> or <span style="font-weight: bold;">bolded text</span> bolded text
[i]italicized text[/i] <i>italicized text</i>, <em>italicized text</em> or <span style="font-style: italic;">italicized text</span> italicized text
[u]underlined text[/u] <u>underlined text</u> or <span style="text-decoration: underline;">underlined text</span> underlined text
[s]strikethrough text[/s] <s>strikethrough text</s> or <span style="text-decoration: line-through;">strikethrough text</span> strikethrough text
[url]http://example.org[/url] <a href="http://example.org">http://example.org</a> http://example.org
[url=http://example.com]Example[/url] <a href="http://example.com">Example</a> Example
[img]http://upload.wikimedia.org/wikipedia/commons/thumb/7/7c/Go-home.svg/100px-Go-home.svg.png[/img] <img src="http://upload.wikimedia.org/wikipedia/commons/thumb/7/7c/Go-home.svg/100px-Go-home.svg.png" alt="" /> Go-home.svg
[quote]quoted text[/quote] <blockquote><p>quoted text</p></blockquote>
(usually implemented in more advanced ways) To quote:
quoted text
[code]monospaced text[/code] <pre>monospaced text</pre> monospaced text
[size=15]Large Text[/size]
(The unit of measurement varies with each BBCode variant and could represent pixels, points, or relative HTML sizes.) <span style="font-size:15px">Large Text</span> Large Text
[color=red]Red Text[/color]
or
[color=#FF0000]Red Text[/color]
or
[color=FF0000]Red Text[/color]
(Both HTML color names and hexadecimal color values are generally supported, although on some boards, you must omit the # from selecting a hexadecimal color.)
<span style="color:#FF0000;">Red Text</span> Red Text
[:-)]
this would be another way to use the [img]url_img[/img] and must be pre-configured for the forum administrator
(And other emoticons, depending on the variant)
<img src="Face-smile.gif" alt=":-)"> :-)
(Specific image and size vary)
[table] [tr] [td]table data[/td] [/tr] [/table]
(Rarely used)
<table><tr><td>table data</td></tr></table>
table data
