I’m looking to gift a book to a couple college graduates in my family but not sure which one.

The easiest that comes to mind is a more deregulated MLS that's for everyone.

This is the easiest way but really the sister needs to handle it.

(If you are not familiar with these concepts, the easiest way to determine value is to simply pay for an appraisal).

It is where I started and was a staple for me to grasp all of the basics for getting started in real estate investing.I'm in Boston as well, and it's certainly not the easiest market to invest without a lot of money.

I gift 9V batteries at Christmas, for the smoke detectors.

Focus on that gift, the reason why all these foreigners come here and CRUSH IT is because they get it they see America as we all should a golden palace where how far you go in life is only dependent on your work ethic. 

Depending on your market, finding comps will probably be easiest using the MLS.

That good friend of yours who personally knows an area or a good investment realtor in a particular area will deserve a huge Christmas gift from you.One caution - I've invested in Military/college towns. 

I was not sure if it would be easiest to just take out a percentage or a set figure.