I have never bought any kind of precious metals, so please excuse my ignorance. I went to some of the sites recommended here to browse a bit, and see that coins that seem to be of the same exact weight and purity can have vastly different prices depending on condition and year. Does that kind of thing matter if you are only wanting to have some gold for emergency and aren't a collector per se? (For example, if I wish to use the gold or silver to trade for a necessity in some dystopian future, will those things matter any more?) This is probably a dumb question, so I apologize in advance.
Just one opinion from an experienced metals buyer:
Stay away from the numismatics (i.e., collectibles), which will carry higher premiums for the same weight.
Stay away from "rounds" (i.e., slugs of metal minted by private companies), because they are less liquid (i.e., suspected by potential buyers of being fakes).
Go with Silver Eagles (American) or Silver Maples (Canadian) with a "BU" rating ("Brilliant Uncirculated").
If you go to Apmex of Gainesville, this will be your cheapest option (and the most commonly purchased). These are produced by the mints of their respective countries, and are widely recognized (and therefore less suspect of forgery, and therefore more liquid).
Alternately, buy "junk silver" (i.e., previously minted circulated 90% silver coins). Pre-1965. You need to do a little math to make transactions because of the 90% (vs 100%) thing, but nobody will deny their authenticity.