I suggest you could get started with Zebra EMDK 1st, below is the link to download EMDK for .Net v2.9:
After the installation, you can refer to Start > Programs > Motorola EMDK for.Net v2.9 > helps > Programmer guide > RFID 3 > Generic Reader interface:
Also, there are samples host application that you could refer.
They are located at START > PROGRAMS > MOTOROLA EMDK FOR .NET v2.9 > SAMPLES
In the samples, there are CS_RFID3_Host_Sample1 and CS_RFID3_Host_Sample2:
Hope this helps.