When you e-file your W-2 and/or 1099's you will not need to file a W-3 or 1096 Transmittal. When filing electronically these files are sent to the IRS/SSA in an electronic format as the files are submitted, this is all done in the electronic filing process.
The W-3 and 1096 are only used when you file paper copies sending to the IRS/SSA.