It's always easiest to create a photobucket and post pics using that.
Easiest way to post photos right in threads-
1. Go to
www.photobucket.com (photobucket = PB)
2. Create an account (free!!!)
3. Go into account options. Under album settings,
make your PB Album Private. Edit any other settings.
4. Setup photos on your machine (rotate and size as needed). These should be sized somewhere between 800x600 ahead of time, although PB does have it's own editor and can re-size upon upload, it can get slow. Office picture manager and a variety of other programs allow this.
5. Upload photos using "Upload photos" which shows up right the top center of your PB album. You can upload a whole bunch at once by holding Ctrl.
6. Once they finish they should show up in your album. When you roll the mouse over them, a drop down should appear, one of the options includes a link for "direct link". Copy that, hit the little mountain icon in the reply screen, and paste it in-
The best part of this is the ability to access these photos from anywhere and post across multiple forums if needed once the uploads are done. Also, you can create a new account and leave them public, I'll do this when I am selling a vehicle.
For a thumbnail, you can just right click on the thumbnail PB makes and use that as a link.