Is it true that we only use about 5-10% of our brains?

You cannot think of the brain being used in a percent manner. Different parts of the brain are responsible for different things, and when you are awake, and depending on the activities you are engaged in, different parts of the brain are activated more or less. For example, when you are touching something, a part of your brain called the somatosensory cortex is activated or when you plan movement a part of your brain called the secondary motor cortex is activated. There is however no part of your brain ociated with telekinesis or moving stuff. Sorry.