How Do Collectable Numismatic Coins Get Graded & Certified?

To reach a grade, NGC, PCGS and ANACS have a team of evaluators who
individually inspect each coin, using magnifying lenses to scan for any imperfections. 
After each team enters their individual grades, the team discusses any grading discrepancies to arrive at a consensus. Once a coin is graded, it is put into a clear plastic container know as a 'slab'.
In the slab, both sides of the coin are fully visible, allowing you to enjoy the coin's workmanship.
A tag prominently shows the coin’s type, grade and other information.
The identification number can help you learn if the grade is legitimate,
since the grading companies use a database to discourage fraud.
That hasn't stopped some unscrupulous people from counterfeiting a slab — more on that in a minute.)
The slabs are designed to keep out air, moisture and anything else that could affect the coin’s condition. The slabs are also designed to be tamper resistant, and opening the case could invalidate its grade.
The slab will help protect the coin, so you don’t have to worry about keeping it safe from environmental
dangers—though you should avoid extreme temperatures or long exposure to direct sunlight.
As mentioned, when buying a graded coin, experts say to buy the highest grade you can afford for
the best chance of it increasing in value.
You should avoid buying ungraded loose, or “raw,”coins. If you do, you run the risk of buying a
coin thatis not nearly in the condition you think it is. Yes, you might run across a raw coin that seems
like an incredible bargain… but it could also be a scam. You might end up spending good money only
to discover your deal is a dud.
After you get experienced buying and judging coins,you may be able to find some “raw”bargains.But
be extremely cautious.

• Never clean a coin — water and
chemical cleaners may harm the
coin, lowering its value. Seek
professional help for dirty coins
• Do not store coins in plastic
containers made of PVC — it can
actually be corrosive to coins
• Avoid touching either face of the
coin, use a glove and hold it by the rim — oils or
dirt on your fingers could react
with the metal.