There are lots of chemicals out there to strip wallpaper and none of them are particularly good for you or the environment.  Luckily, removing wall-paper is actually pretty easy without using any chemicals at all. 

Before doing anything, try ripping the first layer of wall-paper off dry.  This is easy to do if you're dealing with older stuff.  If the wall-paper comes off easily, keep going til you've removed the first layer.

NOTE: This will only remove the decorative layer of paper and leave the glue stuck to the wall.  That's okay.

If you can't rip the paper off easily, proceed to score the wallpaper with a utility knife or scoring tool.  This will allow our mixture to be absorbed and loosen the glue.

Once your paper is thouroughly scored or rid of its top layer, mix warm water and some of your eco-dish soap in a spray bottle.  Spray the entire surface and let the mixture soak in for a few minutes. 

Once your wallpaper is saturated with the water-mixture, grab a scraper and, starting at a seem, start peeling the stuff off.

Before re-applying wallpaper or paint, make sure there aren't any bits of straggling glue left behind.  Wash the walls with warm water, let dry and sand lightly if and before painting.