How can you do this? Cus it says on some of the pedals you're about to buy, it says you can use it on guitar, bass, and even vocals. wtf?
it's the same principle, but instead of guitar > effect > amp it'll be something like
voice (mic) > effect > amp (pa sytem or somesuch)

What pedals are you looking at?
Yep. Our singer hooks up to a DL4 delay pedal and a MXR phaser.
Suhr Custom, Flaxwood Rautia or Grosh Tele thru
HBE Medicine Bawl Wah
Analogman BiComp
Texas Two Step OD
Fulltone Ultimate Octave/Fuzz
Boss CE-2
TC Nova Delay
SLO-100, 65 London or Bogner Shiva
Ask me about any of this stuff!

So can you do like everything like distortion/reverb/tremolo/delay/and maybe even wah?

And basically if you have something like podxt live, you can use all the effects on that to your voice by connecting that to mic?

No I don't have a podxt..
You could use any effect but keep in mind they are designed for use with guitar, and there's the possibility that some won't sound 'good' for the same reason guitar effects don't sound right with a bass.