Pros
Great pay for the type of work. You get paid $8.50 an hour to hang clothes all day or work the cash register. If your store makes its weekly goal, you can get bonuses of $25-$80 depending on your position. There are also contests periodically which, if your store makes good sales, can get you lots of "Goodbills" which you can spend at any Goodwill. Depending on your location, there is a surprisingly large amount of really nice things donated that, even though everything has to hit the sales floor before you can buy it, you still get to see the stuff first and sort of get first pick. They promote from within very often, and will transfer people to other stores in order to give them an available promotion as well. They train you in many different areas of the store too, so you don't necessarily have to do the same thing every single day. They are also known to give problem employees second, third, and fourth chances before firing them, so it's pretty difficult to lose your job there.
Cons
Transportation is a nightmare. They can't hold onto drivers, their trucks constantly break down, and they can't figure out how to make an effective truck schedule. Sometimes takes them way too long to fire some lazy employees who don't do their work properly. Oftentimes, instead of firing you, they transfer you to another store, I guess just to see if you fit in with any other group any better. That means the problem doesn't really get dealt with, it just moves. They change their policies all the time too, and they don't have a great system for notifying everyone of the changes. They'll send an e-mail out describing how they want something done, but they won't fully explain themselves, then get mad whenever they get confused responses from managers. Then they'll send another e-mail out further explaining it, and finally after everyone gets it right, they change their minds and say they're going to stop doing it that way now and to go back to the way it used to be.