Wands are an efficient way of packaging Spells so that all characters can attack with Magic. They can also save your Spell-casters a significant amount of Spell Points. About half of the Wands that you will come across are no more than fancy ways to shoot Damage at Monsters. Use them at the first sign that your physical attacks are not hitting or are ineffective. Recharge them if you wish, sell them before they're used up, but don't hoard them for any reason. If you hold on to them too long you'll find that they've become worthless. You won't even need the gold you'll get for selling them.
The other half of the Wands do have strategic uses. You might want to hang onto these but don't hesitate to use them when the need arises.