I need a Google spreadsheets expert

I have 14 farmers market locations with inventory of approximately 40 products. I need my market workers to complete an easy to understand, end of market inventory sheet on their phone. The sheets will have a master inventory list that will calculate how many products I need to restock for the following weekend. I also need a few of the sheets to be linked (e.g. the end inventory of one market is the start inventory of the following market)