You'll have to post it directly, so copy-and-paste. You can create an album to upload small images. Anything really big should be uploaded to an external service like Image Shack and linked with a thumb nail.
If you mean you want to serialise a story you're creating, and you're going to regularly post instalments on the forum, it sounds like something that belongs in the Fan Creations forum, as that is what it is; a fan creation . I cannot tell you if anyone will like it or not, you'd have to post as see what response you get.
Generally I do not make threads for other people, at least not in response to direct requests like this... If you have a thread idea in mind, either you can create it yourself already (in the appropriate forum) and should do so yourself, or it is for one of the series discussion forums, in which case you need to post in the appropriate thread request thread. In the later case you should explain what you want to create, possibly with an example first post, and why you think it will be of interest to other members of the forum. One of the moderators will then approve (by moving your post into its own thread) or reject the request.