You can download an app like imgur or flickr to your ipad. You might need to sign up to them depending on the app. You then upload your images to their site and share the IMG code or BBCODE FORUM link and paste it in your post. The text will convert to the image when you post the reply.
You can also click "Reply" on posts here and upload files onto the forum directly. You only have a limited amount of space and the images will be the small "thumbnail" images.