I am amazed at how many people do not know how to post a screen shot :O But if they are young i can understand
Step 1Find an image hosting website.
I use servimg because it is fast, reliable and hardly any downtime.
And it has the option for you to resize your image to forum size.
So i suggest you use that
Step 2After uploading, they will provide you with a direct URL link to the image.
Copy that link (e.g. http//www.servimg.com/image1)
Come to the forums.
Do this.
And there you have it. An uploaded image =D