http://www.hgtv.com/design/make-and-celebrate/handmade/how-to-refinish-a-dining-room-table

   Materials and Tools:

     stain
     polyurethane
     100-, 150- and 220-grit sandpaper
     stain brushes
     rags
     tack cloth
     orbital or belt sander (optional)
     router (optional)

   Steps:

   1.
     Sand the entire table removing all stain from edges and legs.  If using an
     orbital or belt sander, be careful not to gouge the surface.  Do  most  of
     the  initial sanding and varnish removal with the 100-grit sandpaper, then
     step up to 150-grit and do a final pass with 220-grit to  smooth  out  the
     grain for the new finish.
   2.
     Carefully remove all sanding dust with a tack cloth.
   3.
     Apply stain with a brush, following the wood's natural grain.  Apply stain
     liberally, allow it to soak in for a few minutes  then  wipe  off  excess.
     Tip:  The longer stain sits before wiping, the darker the final color will
     be.
   4.
     Apply at least two coats of stain.  Depending on the desired  color  depth
     and richness, apply more coats. Lightly sand with 220-grit paper and clean
     with tack cloth between coats.  Note: Staining the wood  causes  the  wood
     fibers to swell as they soak up the stain.  The reason for sanding between
     coats is to knock down the swollen fibers to maintain a smooth surface.
   5.
     After the final coat of stain has  thoroughly  dried,  apply  polyurethane
     according  to the manufacturers' instructions.  Apply at least four coats,
     since dining room tables get a lot  of  use.   Allow  the  final  coat  of
     polyurethane to dry for at least 24 hours before using the table.