Don't worry about the 300 DPI until you're ready to print. DPI means nothing to a computer, or television. DPI is Dots per Inch, which is what a printer uses. To display images computers use PPI, Pixels per Inch. What size in Pixels are the images you're going to use? Digital cameras, will give you rough idea of how large a print can be made from the resolution sizes, like 5MP, 8MP and so on. The more pixels you have, the larger the print can be made without any degradation, which is pixelization.
When you first start your project, the resolution settings at the bottom are not DPI, they are PPI. If you select the Printer resolution, you'll notice that it defaults to 600. Again that's not 600 DPI, that's 600 PPI. A computer does not understand dots. The file sizes are going to be rather large when you're dealing with images that need to be large. For the most part, a digital photo that was taken at a setting of 5-8MP (mega-pixels) should work for a print your size. Most of them will print good 8" x 10" photos.
Ron Petersen, Web Board Administrator