Numerous studies have shown that a 10-15% position, rebalanced annually, in precious metals will decrease your overall volatility and increase your returns. Search the net, you will find them.
Also, you are relatively early to this long term bull market in gold and silver, and hence you will encounter a lot of comments like the above telling you not to waste your time and money on this type of investment. You are best served to ignore them and make up your own mind. Think about the internet bubble, late 80's CA real estate, the Niftey Fifty stocks, 70's gold market and early 90's emerging market stocks. Do you think you would have gotten the large number of the above type negative comments (as well as the negative comments in the referenced thread) near the peak of any those bubbles? Of course not, it's when you don't hear them anymore that you know it's time to start selling.
I would suggest you start your forray into the precious metals markets with the following:
http://www.zealllc.com/2002/gold101.htm - Classic article on how to build a gold portfolio. It's starting the get a bit outdated because prices are so much higher now, but still very much worth reading to get started.
www.kitco.com - good articles on the precious metals market
www.tocquville.com - look up their Gold Fund mutual fund. It's run by an industry expert, John Hathaway, who also writes the best gold commentary. This fund would serve as an excellent base for your precious metals portfolio.
www.321gold.com - another website with commentary on the gold market.
www.financialsense.com - a weekly webcast on the markets in general, with an emphasis on the gold and silver market. Check out last Saturday's broadcast hour 2, which was about 5 ways to buy bullion.
http://roger.kwaves.com - Roger Arnold's radio show archives. Roger has made numerous brilliant calls on gold and the economy in general. He is presently bearish on gold, but he offers as good of an unbiased analysis on the economy and gold market as you can find.