Connect a microphone to your computer's sound card by inserting the 1/8-inch jack to the "Line in" port, which usually is located on the back of your computer if you're using a desktop, or at the front, if you're working on a laptop. Plug a USB microphone into a free USB port, if desired.
Launch your audio sequencer, and open a new project by clicking on the "File" menu and selecting "New" in most programs, but the method for doing so varies, depending on which software you're using. Check your sequencer's help section or user manual, if necessary.
Record or program any backing track or instrumentation to go under your vocals by connecting a MIDI keyboard and using your program's sound bank to provide instrumentation or import samples from your hard disk. The method for doing so varies, depending on the program you're using, so consult the publisher's instructions, if needed.
Load and arm an audio track, and connect it to the microphone "In" port on your sound card or your USB microphone. Select your chosen input from the "In" drop-down menu on your audio track, in most programs.
Turn on the microphone, and press the "Record" button to record your vocals by singing into the microphone. Press "Stop" to end recording.
Play back your track, and experiment with your sequencer's effects plug-ins. The method for adding effects varies, depending on the program you're using. Most programs allow access to effects by clicking on a button on the recorded audio track. You also can add effects in real time while the singer is performing.
Plug the jack connector on your microphone's cable into the jack in port on your first pedal. If you're using a 1/8-inch jack microphone, you may need a 1/4-inch adapter for some pedal brands. You can use custom-made vocal units or pedals that are designed for use with guitars or other instruments.
Connect jack-to-jack cables between your other effects pedals if you're using more than one.
Turn on all of the pedals you're using. Connect the final one in your chain to a channel on your mixing desk, and tweak the settings on the pedals to experiment with the sound of your vocals while singing into the microphone.