If you click on insert image, it will bring up another tab. In the top right corner there is a box that says "browse" if you click on that it should take to your saved pictures in your computer. Double click ( on my computer any ways) on the picture that you want to post and it will go back to the insert image screen. On the right side of that box is a image size. I have always had to resize my pictures to medium to get them to post. Once you have done all of that then click on post image.
As my wife says, I am computer challenged and it took me over a year to figure this out. I also had to keep re reading the instructions in the HOW TO POST A PICTURE section
Steve
86 Bronco, XLT, 5.0 EFI, EEC IV, AOD, IFS, limited slip front and rear, 3.08 gears, Tilt steering, factory AC