Let me make sure I understand what you are looking for. you want someone to be able to fill out a couple of form fields, and have them upload a graphic, and a link, and maybe a brief description or something?
how are you storing this info? text file?...do you have a db on the backend? (not that it matters much)--and how are you planning on linking the image to the data?I would recommend using a DB if you can. store the imagename with the rest of the data...nothing fancy.
However, if you can't use a DB, it gets a little quirkier (and a lot more fragile). You still have to have a way to link the data and the image....Id use something like a text file that stores the imagename,description,link,etc in a tab, or comma delimited format. one entry per line...not terribly pretty...but functional.
As for the actual code...most of it is in the manual...look under filesystem functions for fopen, fwrite etc, and be sure to read Chapter 20. Handling file uploads--that should give you all the tools you need to write this script
hope this helps.