What are some things that a fresh Mech. Engineering graduate should know to start a career in MEP?

From Day One, evaluate your options within the company, looking for interesting work and good career-building assignments. Find out where that work is located, and what you must do to position yourself for opportunities. You must take steps to manage your own career. Be constantly on the lookout for more experienced advisors and mentors. Tactfully make management aware of your capabilities and interests and illustrate how you think you can benefit the company in a new assignment. This must be done as a result of a serious examination of yourself and the needs of the company -- in that order -- and by keeping your eye on the big picture of where the company is headed.