You can upload pictures directly from your hard drive by using the "Attach" box. The "Attach" box shows when posting a new topic or a reply, but not when using "Quick Reply". Images must be 200kB or smaller - if they're larger, re-size them.
Or you can host them on a photo site (Photobucket, Village Photos, etc.) and put the url or img link to the picture(s) in your post.
3/2022
I added some software to the site that allows for larger pictures and it automatically downsizes the pictures. Seems to work pretty well, but if the original photo is really large, the compression may still be larger than the 200kB limit. It will either tell you that or it may show an error.
btw, it automatically downsizes the pictures to 1024 wide x 800 high (or whichever is greater), so that fit on the screen better.