As far as staining, there are several ways to do it, but I prefer the easy way. Sand the wood with 120g or so. Apply mineral spirits to clean off any residues and it also pulls off some of the leftover sawdust. Apply the approrpiate stain (I use a 2 in one minwax stain and seal). Allow it to dry and sand with a fine steel wool. This will remove the burrs that are overlooked or sealed in with the polyurethane. Allow to dry for a day and apply a second coat. This coat will make the stain resemble the intended color. Usually 2 coats is enough, but if you need more, repeat with the steel wool. On the final coat, allow to dry for a day or 2 then rub it with newspaper. This will polish it and ensure that the sealant is cured. It keeps it from staying sticky.