Firstly, all of us miners have a conflict of interests which may be introducing a bias toward not wanting more people.
With that said, I'm not sure if mining is a viable thing to be introducing most new users. With the advent of GPU mining, the only people that really benefit from mining are those with gaming rigs. The rest of it just gets hopes up from new users. And business owners may be interested in it, but that's not the key for them. So, thank you for the disclaimer up top. I think I would change the warning to:
"Let's be clear about something: Bitcoin mining is a very competitive business. Just as during the gold rush in Alaska or California, many miners will not make any profit unless they put lots of time, money, and energy into learning how to do it effectively. Mining can make sense if you do it for fun, or if you can do it very efficiently (low electricity and hardware cost)." Adding a story (Gold Rush) lets people tie it back to something they may already know. We already know that the people who made the most money on the Gold Rush were the merchants, and it's probably going to be true here. ATI will make a killing.
You can mine with a CPU, but mining with a graphics card (GPU) is far more efficient. Modern graphics cards let you use their power to solve certain types of high performance computing problems and Bitcoin mining is one of them.
My Edit:
You can mine Bitcoins by using the "Generate Coins" option in the official Bitcoin program, but don't expect anything spectacular! Even the most modern Processors could take years to find a single block. Over time, miners have found that mining with a graphics card (GPU) is far more efficient. Modern graphics cards let you use their power to solve certain types of high performance computing problems and Bitcoin mining is one of them.
"the most cost effective at the moment are..." should be changed to "...at the moment is" since you only listed one card. Giving the most efficient, and the most powerful might be a good idea, and would also give people the idea that the card that does the most work might not be the best choice, and there is a tradeoff for their mining preferences.
That way you get a steadier income, but give up a small percentage of your revenue to the pool operator.
My Edit:
That way you get a steadier income, but maygive up a small percentage of your revenue to the pool operator.
Also, you should direct people over to bitcoin.org's forums for more information, since there's a number of people who like to help newbs.