Near Earth Asteroid 2012 LJ will zip past on 10 June, at around 18:43 UTC. It's around 15-47 meters across and will come within roughly 1.6 LD's of Earth (one LD is the distance from Earth to the Moon).
Orbital information can be found at JPL here. It was only just discovered, so the orbit is still being refined. Small, fast and dim this will be a difficult object.
If the weather is kind you will need to plan carefully. Since few planetarium programs can calculate a correct ephemeris for objects that come close to the Earth so you will be better off using the online ephemeris service provided by MPC, being sure to generate a local topocenentric ephemeris:
Spain MPC Code I89, Nth America MPC Code - H06