You're not an idiot, it's tricky in the beginning, but if you want we will help!
Ok:
First upload a picture.
Use the upload images in the menu just under the Simviation sign. You'll get a page with 8 free spaces. Choose a shot ( start with one) and write down the title on a piece of paper.
(ex. my shots are called: Omag-Iberia1.jpg)
The,n push the upload button. You'll get a message with the
http://www.simviation.com/yabbuploads/yourpic.jpg line.
Now go to the screenshot forum and start a new topic.
To add a screenshot use the little pic in the second row with signs, the 4th from the left, next to the envelope.
it goes to
[img]URL[/img+] ( <-- i added a + to make this line visible)
then form [img]http://www.simviation.com/yabbuploads/yourpic.jpg[/img+]
and change the yourpic.jpg with the name off your file.
Using my example this becomes:
[img]http://www.simviation.com/yabbuploads/Omag-Iberia1.jpg[/img+]
Make absolutely sure that the name of the file matches, pay attention to dots, spaces and capitals.
Now save the topic and your picture should appear...
Be sure not to use that +!