A mistake on a Form 4 is handled very quickly by the ATF.
What usually happens (usually) is that a clerical error on the part of the individual filling out the form 4 is identified by the examiner, the forms are returned to the person/gunstore selling the item and the error is corrected and sent back to ATF examiner directly. The corrected form is processed and the stamped form is sent out usually (again usually) in very short order.
Oh and the error is always identified by the examiner so it can be corrected.
If your gunshop is telling you that you have to start the whole process over (to include payment of the 200 dollar tax), I'd find another gunshop to do business with as they (the gunshop) are running a game on you.
In fact I find it very hard to believe that your gunshop is allowing you to fill out the forms, especially if you have no experience in doing so (not that its hard, it usually only takes about 3 minutes to fill one out).
With respect to your request for a website to go to that shows how to fill out the forms go here:
http://arizonagunlist.com/How_to_bu...able_living_trust_without_a_CLEO_signoff.html
They show completed form 4 (albeit for a trust) and that should help you figure out what has to filled out.
With respect to attaching photo's, I use a glue stick. Never had a problem with them falling off.