Iman:
Iman (Faith) means to believe in the heart, to confess by the tongue and to act with the parts of the body. The pillars of Iman are six (i.e. to believe in): 1. Allah (SWT). 2. His Angels. 3. His Messengers. 4. His Books. 5. The Last Day. 6. Divine Preordainments, good or bad.
Ilm:
Ilm means knowledge, to know and understand. To know what and how to practice in life from the rules by Allah is known as Ilm.
Amal:
Amol means practice. Practicing order of Allah as of teaching of Hajrat Muhammad (Sallallahu Alaihi oa Sallam) is Amol.