Salaam and Greetings of Peace:
The Prophet (pbuh) has said:
“If one of you is concerned about some practical undertaking, or about making plans for a journey, he should perform two Rakats (cycles) of voluntary prayer. Then he should say the following dua:”
O Allah! I seek Your guidance by virtue of Your knowledge, and I seek ability by virtue of Your power, and I ask You of Your great bounty. You have power; I have none. And You know; I know not. You are the Knower of hidden things.
O Allah! If in Your knowledge this matter is good for my religion, my livelihood and my affairs, immediate and in the future, then ordain it for me, make it easy for me, and bless it for me. And if in Your knowledge this matter is bad for my religion, my livelihood and my affairs, immediate and in the future, then turn it away from me, and turn me away from it. And ordain for me the good wherever it may be, and make me content with it.
– Called the Salat-ul-Istikhara, or The Prayer of Guidance, it is adapted from the excellent and beneficial Simply Islam blog.