a online software for a printing shop. ? Something like this. There's an online web portal to upload what the user needs to print from the shop. So there's a user base and there should be a database. So the database part is covered. Since it's online, server scripting also there. also add security layers to it.
In the other end, there's a desktop application which downloads the documents which needs to be printed and the software will be print them, or notify the person in the seat of the printing shop to print them. So there's a desktop application too. It will cover data transfers between online servers and handling printing devices with the software.
As soon as the printing is done, online notification and an email will be sent to the person who submitted it and he can come or the printing shop can arrange some other way to deliver.
Also i am considering mobile app to submit documents to be printed. Also can create a sms gateway to notify user when the job is done.
Some of my other suggestions are :
Elasticsearch-- this is my favorite and this is an up coming tool for analysing system logs.
Internet of Things : example amazondash how and where can this be implement in the online trade.