I posted this as 4.7 but 5.0 applies as well.
I've reserched how to create a custom module and i feel pretty comfortable about creating a basic module with multiple fields, etc.
What i'm not so sure about is making one of those fields a file upload field. in particular a MULTIPLE FILE UPLOAD filed that assoicates multiple images with a given node but does NOT make the imgs nodes.
Would any body have a module that might model this behavior or provide some guidlines (note i do NOT need help with teh general module ONLY the multiple upload field and how to make it work in drupal forms api).
The main difficulty is this:
If you allow multiple img uploads without predefining how many you will allow, the user must be able to browse locally , select a file, submit and THEN be allowed to do that again for as many imgs as they want to associate and upload with the node withOUT losing the rest of teh form fields every time they hit submit to enter a new img. Hope you follow that.
I can see a couple of ways to handle this:
1) somehow (i don't know how??) make the img upload field part of the form a "sub"form of the main node so that when you submit on the img field, you do NOT lose the rest of teh form data or vice versa.