Yeah sorry about that, is there a better site to use. I'm not exactly familiar with these kinds of things even though it's probably been explained like a hundred times.
I find Imgur to be too impersonal and too public.
Try Dropbox. It's free, with limits that should be fine for images. It tries to get you to install a PC based uploader and manager, but I don't trust it enough to do that.
WARNING
You must manually resize the image to 500x500 or lower. Failing to do so will result in the image showing at full size and probably breaking a rule of the forum.
Where "img" would go in normal formatting replace it with, "img width=396 height=500". Changing the numbers to make the ratio proper.
For example, this 1920x4320 image should be "img width=222 height=500". Don't forget the brackets. When in doubt, use Preview.