A few suggestions if you are looking at bullion coins:
* Get the red book (RS Yeoman). Tons of good information, though the prices are completely out of whack (book prices are too low)
* Get a digital coin scale. Sure, you don’t have to do this but the weights of the coins are well known AND hard to fudge because gold is so dense.
* Don’t overlook ebay — but be very diligent. High NGC/PCGS scores probably won’t be very useful to you.