Automotive batteries do not recover very well from complete discharge and you will probably find it is time for a new battery... A good battery should run a radio for days without going flat, it is only things like headlights that can drain a battery overnight. Of course if your radio is connected to a 1000W amplifier and boom boom speakers operating at full volume then maybe that would also do it!

However, even with a very flat battery you should still be able to jump start the vehicle if your jump leads are good enough and are connected properly to a car with a similar sized (or bigger) battery... you car basically uses the other cars battery to start and the state of yours is pretty much irrelevant. Make sure the donnor vehicle is running above idle to ensue that its alternator is pushing adequate energy and then your car should should start. If your engine wont turn then the chances are you have poor connections on the jump leads. Any form of poor connection will lead to a high resitance and this will limit the power that you need to crank the engine.