The motor was built buy a reputable marina that has a full engine shop specializing in rebuilds and long blocks. I assume its good.
The motor has been assembled and sitting in a crate since 2011.
Is there anything that I should be doing before installing it?
I understand from this board that valve springs can go bad when sitting under pressure for a long time?
Thanks in advance

THats not all that long, but I would at least re prime the oil system

I would be more concerned about valve spring fatigue from running hours than I would be from sitting for a couple years... As recommend prime it and run it. I would get it hot and change the oil after a few hours of run time. Condensation and rust is an engines biggest enemy while sitting unused. And a new engine will always have some level of contamination from rebuild. Use a cheap oil to do this, and refill with your preferred brand and grade following first drain.

sitting with a few of the valve spring compressed for a long period of time is a killer..seen them loose 30-40% pressure...

$150 set of springs is cheap insurance from having a piston kiss a valve. Doesn't take long to swap them out either. If the motor is gonna spin any kind of rpm I would atleast check them with a spring checker. Maybe 15 minutes of work...