The ReStore is like a thrift store, sorta. It's run on donations, but the donations come from all over. As an individual you can give them stuff if you want, but more often they prefer items that come from businesses (contractors especially). I was in there when they got a load of granite, and that was pretty cool. If you need granite, I mean. What thrift store has granite?
What you need to realize is that they have a really eclectic selection of stuff. One area is completely geared towards doing stuff around the house - you can find things like the aforementioned granite, doors, windows, cabinets, sinks, toilets, tile, electrical, who knows. It just depends on what has come in.
The other section is more like your typical thrift store, where you find furniture, and well, mostly furnishings - think mostly furniture, but you can also find pictures and other accessories. I don't think I've ever seen clothes there, but that doesn't mean that they don't have them. We have purchased small appliances (microwaves) and a number of pictures, which may be the best deal in the place.
You can find monster pictures that are way cheaper than if you bought them elsewhere. Don't know if they are taken out of homes when they are remodeled, or if they are cleaned out of foreclosed homes, but they are definitely good to find here. We actually have times where we have so many that we can't hang them all.
As Julia says, the furniture is totally hit-and-miss, and we find that for what they have, it's usually (way) overpriced. But you might be able to find something cool, so take a look.