Jessie, so nice that you are having fun with the progressives here.
The easiest way [for me] is to save the original PSD/Tiff file under the name [like Jan Progressive] in a new folder labeled GDS Jan Progressive [as an example]. Makes it easy to find that month's progressive. Then when I reduce the image and save it as a jpeg file, I label eash one with my user name, month name, and step number.... ie.... BrightEyes Jan Prog Step1. End up with the same number of jpeg files as there are steps inside that month's progressive follder. BTW... as a hint - never flatten the PSE/Tiff original file as then you can't add more layers to it. [Learned this one the hard way on my first progressive.]
I always put the the kit name and link to kit in the description box as well as in the credit/store item boxes. There has been some problem finding it from clicking on the store item boxes.... sometime it will say 'item not found'. By including it in both places - a person can find the kit easily. I will also list the kit by name/designer in my post - if I remember.
I also like to copy and paste the step information into each step description box..... being sure to go back and repaste the kit link information as it gets cut short when you do the copy. So... step 2 would have the info from step 1 and step 4 would have the information for all the steps up to that step. Hope that is clear.
Have fun and enjoy the progressives.... they are additive.
ETA: for non-GDS items list them under the GDS but do not link them as outside linking is not allowed. You should list the kit and designer names do not list the other store name/s. Read the Gallery TOUs
here. The progessive rules say you need to use at least 50% GDS items.