I know how to make minor changes to the source code but I usually get in over my head really quickly. You can use Visual Studio to edit the source and compile your own binaries. Not sure what the most commonly used version is atm. The database can be altered through command line or with something along the lines of Navicat or HeidiSQL.
Visual Studio -
https://www.visualstudio.com/en-us/n...munity-vs.aspx
Source Code -
https://github.com/EQEmu/Server/
Most recent database - edit.peqtgc.com/weekly/peq_beta.zip