1. You can purchase individual coins. There are two basic types of coins, bullion vs numismatic coins. Bullion coins are valued primarily for the value of the content of the metal. For example, a 1 ounce gold coin would contain nearly an ounce of gold. Numismatic coins are valued for both the content of the metal and the rarity of a particular coin, for example, a rare year or mint. Some sources are GovMint.com,American Mint,and Gainesville Coins
2. You can purchase bullion through companies such as BullionVault.
3. You can purchase ETFs. ETFs are “Exchange Traded Funds” that invest in gold or gold futures. There are a number of well-known gold ETFs available that own gold bullion (e.g. massive collections of gold bars) SPDR Gold Trust (GLD), iShares COMEX Gold Trust (IAU), and ETFS Physical Swiss Gold Shares (SGOL). GLD and IAU vault their gold in the United States. SGOL vaults its gold in Switzerland. Their costs (“expense ratio”) as of today are roughly equivalent, 0.39% to 0.40%. The lower the costs, the better.
Some ETFs track gold futures, PowerShares DB Gold Fund (DGL) and UBS CMCI Gold Total Return (UBG). DGL’s cost (“expense ratio”) is 0.5% and UBG’s cost is 0.30%.
4. You can purchase shares in mining companies. For gold mining companies, you are purchasing the management in the company, their proven reserves, sovereign risk that the countries they operate in will not nationalize their operations and a bet on the future price of gold. Shares in gold mining companies have the largest number of variables. For more information, please see this article.