I stained the floors and left for 5 days. Didn't realize the floors puddled really bad. I need to know if I need to resand the floors or what do I do?

If it is in fact that stain that puddled, then yes, you would need to completely resand and start again. The stain is the bottom layer. And you can add stain on top of the poly to even it out. It won't stick.

Debbie Gartner, aka The Flooring Girl

stain is designed for the excess to be wiped off while wet. If you are trying to obtain a very rich/dark color puddling the stain on or multiple applications of stain will cause major adhesion problems of the finish coats as it will have nothing to bond to and will result in peeling and or blistering if you can even get it to dry. The correct way is thru proper sanding techniques. Dont over sand the floor, final pass should be 80 or 100 grit paper no finer, if that isnt good enough you will have to open the pours of the wood fiber back up by water popping the floor before staining. It's not easy!