Good call
buttrick 
There is a "Sticky" on the AH & N main page with three pages of tips on posting images, but this is what I did for image posting:
1/ Create a free account on Photobucket and upload the image (JPEG or GIF).
2/ Double click the thumbnail image that will appear, it will come up as a full-size image, to the right of this will be a block of Links, click on the
Direct Link URL and this will copy it to your clipboard.
3/ Create your Silhouette Challenge post and insert the image using the format [img]
Paste the link here using Ctrl V [/img]
4/ Preview/submit your post
Note the SQUARE brackets and don't have any carriage returns!
The image should be no wider than 850 pixels, I usually use around 640 (re-sizing can be done on Photobucket) but I usually get it right using MS picture editor.
Good luck
Edited to say Guten Tag Reg, you posted while I was typing
, off to work now, will try and get back during breaks!