An ex pen is probally the best way to potty train , at least I think so, you didnt say the age of your pup, but if your working 8 hours it will be impossible for any puppy to hold it that long expecially if you have also kept your pup in a crate all night long!! Attaching an ex pen with a puppy pad , bed and toys will enable your puppy to excersice , play, pee and sleep. You can also just gate them in them in the kitchen or bathroom As for peeing on your hard wood floors you can get a shower curtain liner for 1 dollar at the dollar store and put it under the ex pen.. there are different kids available on line but the one above looks wonderful!!
http://www.jcpenney.com/jcp/X6.aspx?...%20Safe%20Yard
this is the one that I used