Easiest way for me is to have them uploaded elsewhere on the web, such as face book, or a web photo hosting site such as photobucket. Then mouse over the image and right click, highlight properties, then highlight the address and copy it {typically the address will end in .JPG.}
Then open your new "reply to thread here at TBN, and paste it between the following HTML.
yourcopiedaddressgoeshere[/IMG ] I intentionally left a space at the end between the "G" and the "]". Otherwise you would never see the formula, your entry will have NO spaces anywhere in the formula..
Here is one from FB using the above formula.
[IMG]https://scontent-b-iad.xx.fbcdn.net/hphotos-frc1/162990_1370688846092_5042903_n.jpg
I know it sounds like a lot, but after a few, you'll be able to post an image on any forum..