You don't need a web hosting site now like you did in years past. Uploading a picture is easy as long as the picture is under 300kb.

Check the size of your picture. If you need to make it smaller, use the paint program already on your computer (under accessories in the start menu).

1. Hit PostReply & Write your message if you have one
2. Click on "Embed picture in post" at the bottom of the popup box
3. Click on "Click here to upload" and browse your computer for the pic.

Easy as 1-2-3