1st.Convert your images to a .jpeg. To do this you open paint look in your picture files select the picture you want, select open with and paint. Then click save as and select .jpeg from the dropdown menu.
3rd.Use the 'Img' tags! Press the 'Img' button then the URL to the pictures and then press the 'Img' button again. I will look like this:
[img]www.image.com[/img] where www.image.com is the location to the uploaded file.