Ok,
here is a "mickey mouse" version of how to use
www.tinypic.com
Find the picture you want. I find google images very useful -
http://www.google.co.uk/imghp?hl=en&tab=wi&q=
Right click on the image you want to use. A menu should appear. Choose "save as" and this will save the image to your computer, usually in "my pictures".
Click on the above link for tinypic.
1/3rd of the way down the page is an empty box with a "browse" button next to it.
Click on browse. This should open your picture folder in your computer.
Double click on the picture you want to use.
Click on the "host" button.
Wait. This may take about a minute if you are on dial up.
You will now get four boxes, each with a bit of gobldegook in it.
The top one is an Url
The next one is a Tag
The next one is an Img
The bottom one is a link.
It is the Img one you want!
Highlight this bit, right click and select copy from the menu.
Come back to YD (or wherever) and right click again in the Reply box on here. Select "paste". This should copy the bit of gobldegook onto here. It should have [IMG] at the start and [/IMG] and the end.
[IMG]
http://tinypic . com/p4oyd [/IMG] It should look llike this but without the spaces.

and you should get this!