There are many ways to make iced coffee, and every summer there seems to be online discussion about the best way to make it.
One barista has written a technical account for why cold-brewed iced coffee works well. Cold-brew is where you use medium- to coarsely-ground coffee beans and let that steep in either room-temperature or refrigerated water for 12-24 hours. http://beansandwater.tumblr.com/post/22588752858/iced-coffee The barista there is named Lorenzo Perkins, and he's very well-respected in coffee circles, having recently placed well in the SCAA barista competition. At the end, he suggests a "hot cold brew," which is something that other baristas have recommended in the past. A couple of years ago Colin Moody, an Intelligentsia barista, performed such an experiment--http://brewtasterepeat.wordpress.com/2010/10/05/cold-brew-hot-bloom/--and Jesse Raub likewise recommended such a tactic at his bitterpress.com blog, which is the best coffee-brewing blog around, in my opinion.
Nick Cho, another big name in coffee, wrote a rebuttal to Perkins' description of the cold-brew process. You can find that here: http://nickcho.tumblr.com/post/22596930539/iced-coffee. Cho, however, apparently hasn't tried the hot-cold method, so his comments don't apply to that. I've tried the method, and I feel like it's an improvement over conventional cold-brew. It works best with bright coffees, African coffees in particular. With African coffees, even a conventional cold-brew can produce a great black result; a standard Colombian, on the other hand, would produce a more mellow result, which would go nicely with cream/milk.
Cho, and other coffee professionals like George Howell and Peter Giuliano, prefer the "Japanese Iced" method, which means brewing double-strength directly over ice. The key is to cool the coffee immediately, to lock in flavorful acids. This is usually accomplished by dripping directly over ice. http://vimeo.com/41298356
What's not mentioned in the above video, is that you will want to compensate a bit for the fact that you're using less hot water. You're using less hot water, so you're extracting less than you otherwise would. You can compensate by adding some stirring, grinding more finely, or extending the bloom time. An immersion-method like Aeropress is slightly easier for the Japanese iced method.
Finally, you can do a brief cold-brew. The Aeropress works nicely for this. Instead of steeping for 12-24 hours, you can steep for 2-3 hours while using a finer grind.
Long story short, there are lots of ways to make iced coffee. The best is whichever one you happen to prefer. I go with the "Japanese Iced" via Aeropress myself.