The limit on photos is:
Allowed file types: pdf, jpg, gif, mpg, png, mpeg
Restrictions: 3 per post, maximum total size 5000KB, maximum individual size 5000KB
And the best way to accomplish this is to reduce the images to a reasonable size, say 250 or 300 KB, as this size will be easier for people to see on one page.
The area to post pictures is if you scroll down below the typing box, to the area that is headed "Attach", and hit the Browse button, and then proceed from there in the normal way to scroll through your computer to where you have your images.
But, best to reduce your pictures and place them in a separate file before doing the above.