Adobe offers several PDFs with some information regarding scripts.
My journey about scripts has started 5 years ago, when I was a photo-editor.
That journey still continues nowadays, I have even invented my own job in the company and I do only programming for photoshop, bridge, etc.
It was not easy to get all the info I needed and much of the help I got, was from other script developers on the Adobe script forums.
For a team of 20 studios, 24 photo-editors, and a huge amount of images to shoot and edit (more than 6000 images per day), scripts are really, really important.
Some people are building scripts to try to make money, some for work (my case) and some just for fun and personal use.
Info about scripts
Forums of users (requires email login registration, or adobe ID)
photoshop script forum
bridge script forum
indesign script forum
coding-corner forum (creation of adobe app extensions, etc)
PDFs available
(download the version you use, then search the pdf docs in the folders)
(there are a bunch of scripts available to start studying and testing. Ask questions in the forums to the other users. The answers come from other users like you, and rarely from adobe)
photoshop/sdk
bridge/sdk
indesign/sdk