Im no professional, nor am I a coin dealer, but I've been collecting for 2 years now and I am up to about 600 unique pieces, including my personal favourite, the Royal Canadian Mint's $5 1 oz 9999 silver clad in gold coin commemorating both the 2010 olympics and the Men's hockey triumph.
Step 1: Items You Need
2x2 paper coin slots
5x4 plastic sheets to hold 2x2 coin slots
Time, and lots of it
Step 2: 2x2s
You can get many different sizes of these slots, for example, penny, dime, quarter, half dollar, and extra large. Choose the proper size for your coin and do the following:
1. Center the coin in the plastic.
2. Fold the slot in half over the coin.
3. Holding the coin on either side, pick up coin and staple the bottom two corners.
4. In pen, label the year, country of origin and face value.
Step 3: 5x4s
Slide the coin like so into one pocket in the plastic seet, and there you have it, a coin casing that will always stay good.