The first thing I would suggest you do is organize the collection by country. In order to gather any information about a stamp, you would first need to know what country it is from. In order to do this, the most cost effective method would be utilizing a stamp stockbook. These are bound stockbooks (just like a book at the library) that are available in different sizes and configurations. You could also purchase stamp stock pages to place inside of a ringbinder as well which many stamp collectors do. There are also hingeless stamp albums available for your mint stamps which are the optimum way to collect. But in reality, this will cost you more and since you are just trying to get organized, stamp tongs (which are like tweezers) specifically designed for stamps. this will get expensive. When you are placing a stamp in any type of system, you should use stamp tongs.
Lastly, once you are organized you could then either bring the collection to a local stamp dealer, or alternatively try to first value the stamps themselves using Scott Catalogs which are the industry standard. These books, though quite expensive, do provide current market values of stamps. These are all organized by country which is why I suggested this method earlier. I wish you all the best with your new collection. Hope you and your family enjoy all the work and effort your grandfather put in building your collection!
