Attempting to Understand Transistor Specs and Pick One
Don't use a bipolar transistor. Use a MOSFET instead. 


Their on resistance is on the order of milliohms (so virtually zero voltage drop across the transistor)
Have high impedance gates (no current flow into the gate)
Come in numerous packages (easy to breadboard).








simulate this circuit &ndash; Schematic created using CircuitLab

For your application, and with the circuit I included, you'll need to look for the following parameters.


N channel enhancement MOSFET
Logic Level gate with less than 3.3V drive voltage
Your current will be low, be mindful of it, but I'm not seeing any on Digikey that will not work for you.
The maximum \$V_{DS}\$ will no matter much either. The lowest I'm seeing is 5V. You'll be fine there. 


For starters, here's an example.