I decided to spread a little of my knowledge on acquiring voices and voice acting yourself.
I, myself, am not an impressive voice actor, even now. Back when I first started two years ago, I was even worse. So I'm not going to try to educate you on how to voice act. For that, MasakoX, the great VA of the Abridging Community has set up his own show on Blip.tv.
Now, onward to other topics.
Equipment
The first voice acting gig I tried to land was for Toonlord's One Piece Abridged. I used the voice recorder on my .mp3 player and it sounded terrible.
He did give me some advice though:
"The audio was a tad bit hard to understand, try to speak clearly into the microphone and be a bit further away so that it won't produce static as much. However if it is beyond your controll due to the equipment itself, then I understand."
The limitations on my equipment made it impossible for me to be heard. So here's what I currently use:
I currently have a $30 microphone headset that sounds awesome. However, most people use a simple $15 mic from Wal-mart, and if you know how to use it, then go for it. I had one before this one. I've seen some people pull it off with their desktop mic, but I wouldn't advise it.
The only thing I can really recommend is that you use a free program called Audacity. It has everything you need, from changing the pitch, to changing the speed, to noise and click removal and is even able to get rid of lyrics in a song. Its awesome.
Getting Voice Actors
With Inuyasha, I started with posting a video to my youtube account. It attracted three people: Toonlord(Sesshomaru, Miroku, Inu no Taishou among others), z55177(Kagome) and Arahime(originally Sango, and Rin).
When that seemed to stop working, me and z55177, who eventually edited the film, went and started asking amateur voice actors. There are tons of voice actors on Youtube, you just have to find them. In this way we got the rest of them.
But recently with the newest movie, we ended up also posting an ad on the Voice Actors Alliance Forum. You probably need a good bit of experience with the VAA before attempting that, as I learned.
This forum, once it gets off the ground, will be a good hub in which to exchange voice acting talents and whatnot.
So, to break it down:
1) Post an auditions video
2) Ask for help from amateur voice actors on Youtube
3) Post here.
4) Post an ad on the VAA forum, if you have a good amount of clout and experience, otherwise you'll just end up getting knocked back into obscurity.