Ahhhhh.... something I can help you all with....
Top quality prints will be between 240 and 300 dpi to get sharp images when viewed from 2 to 3 feet away. If you are looking at the poster/print from more than 6 to 8 feet, 150 dpi will do it. Pretty much any digital photo will have to be scaled up to get to a poster print. To get a good quality *********** from a digital photo you're looking to start with an 18 to 20 megapixel image. Shots above 30 megapixels enlarge easier. More important than the size of the image (within reason) is how sharp a photo is. In short, good sharp photos are best. If it is even a bit out of focus, the *********** will make it worse.
Bottom line 18 megapixel minimum, good sharp photo. You want a photo from an SLR as opposed to a point and shoot camera. I won't get into a huge explanation, but suffices to say that a 24 megapixel pocket camera will NEVER equal the quality of a 24 megapixel SLR. The main issue is the physical size of the sensor. A camera phone would be even worse.
If you want top tier prints.... a 24x36 image would be a 77 megapixel image. It's not difficult to get there.... you just have to start with a good photo...
