Enterprise Programs

Over the next year I need to prepare to take over some application development internally. We currently outsource this. My plan is to do a rewrite of the software in C++ using Qt. As the program stands now it needs this. Anyways, the program is used to create deals and sell equipment to customers. I want to write the server side for Linux. I can't seem to find any books about writing enterprise applications that rely on a server. Does anyone have a recommendation for me to read?

I will most likely need to write some daemons, and connect with an external SQL server our DBA would control.