QUOTE(all ears @ Sep 25 2007, 07:35 AM)

Violin polish will help a little with the old rosin and the scratches (so they don't show up too much), but don't use furniture polish or wax etc - wait till you get a chance to get some from a violin shop, and ask their advice too.
Depending on what the instrument is and how much it is worth, I would recommend letting a luthier clean it up for you and touch in the scratches at the same time.
I've tried the so-called 'violin cleaner' liquid myself and believe me, it's far more difficult to use than you might imagine. Rub too hard and you start lifting the varnish surface. Don't rub hard enough and the cleaner forms a dull hue that doesn't appear to want to come off!
In the meantime, make sure you dust under the strings, fingerboard and tailpice after playing. This will prevent any further build up of rosin. Regrettably, many students think rosin dust left on the violin looks cool and gives the impression that they are always practicing. In reality, the dust becomes a sticky glue that gradually bonds itself to the varnish. It can, in time and given enough build up, actually affect the tone of the instrument.