Furniture and Furnishings - revarnishing my italian furniture

Hello all,
I have some Italian furniture that i want to re-varnish, but was wondering how and what to use. this is the first time it is being varnished since i purchased it several years ago, and all I now is that the finish used was coloured (looking at the bottom of the feet, which are a lighter colour). I've read that the wood needs to be sanded first, but am worried this will ruin the dark colour by revealing the lighter colour of the wood underneath.
Please help :confused:

P.S. i've purchased a quick drying clear gloss, that says it gives an acrylic finish, is this good ??

Before recoating a piece with finish it is necessary to determine what type of finish is already on the piece. Almost all factory finishes, both in the U.S. and abroad, are lacquer.

I do NOT reccomend a polyurethane, standard varnish, or acrylic over this finish.

To determine what you have for a finish, take a rag and dampen it with lacquer thinner. Rub a small hidden area (like the back of a leg) gently with a circular motion. If the rag starts to drag/stick as it dries out, you've got a lacquer finish and should recoat with lacquer. If not, it's probably a varnish of some type and the finish you bought will probably work - but you have to lightly sand the old finish in order for the new finish to hold.

If it is lacquer, you don't need to sand in order to recoat - just clean thoroughly before starting and allow to dry completely.