I've never really been into coins. Although many are nice from a collectors perspective. I like that American Eagle though. Thought about that.
Coins are easier to verify authenticity, and the premium is no greater than for the one-ounce bars. So I conclude it makes the most sense to buy bullion coins for investment purposes.
What Has the Government Done to Our Money is absolutely the gold-standard when it comes to explaining sound money ideas. Get that one for sure.
Also, when it comes to investing, I recommend:
The Permanent Portfolio
and
Fail-Safe Investing: Lifelong Financial Security in 30 Minutes
Holding gold is an investment, as I understand investment. We invest to protect and to grow our hard-earned wealth. Does gold do this? Yes. Gold can certainly protect your wealth in some specific environments -- in natural or political disasters, financial crises, and any number of worst-case scenarios. It can also certainly grow your wealth, during times of high inflation. Now it's true that gold pays no dividends and no interest. But that doesn't make it not an investment.
It grows via capital gains. It doesn't matter how your investment grows. Dividends, interest, and capital gains all put money in your pocket and all compound just the same (except the different gains are taxed differently). $200 of gold in the year 2000 is worth over $1,300 today, 13 years later. Does it really matter that no one sent you an annual dividend check? It all works out the same. Example: if Apple stock triples, it tripled, even if they never paid out a dividend during that time. You still tripled your money.
Gold is a perfectly legitimate investment, and is, in fact, an essential part of a wise investor's portfolio. Without gold, you simply are not protected should a period of high inflation begin.