Insert images directly on the forum, the button "Upload attachment". They stored on our forum forever.
Also, if your image resolution is 100500x100500 pixels with a size of 20 megabytes in BMP format, reduce it to a convenient size (for example,800x600 pixels), and save it in PNG or JPG format. A free program Paint.net will help you to do so.
Moreover, we recommend the service TinyPNG. It can reduce the file size without quality losses.
Thank you for your attention!