Hey Jacob,
A full size A1 print is 33.1x23.4 inches. When blowing a photo up to this size, there are two things that will affect the quality of the print. 1) the camera megapixels. But this is fixed at 10mp for your camera. 2) the resolution and interpolation of the program and printer you are printing with. Personally, I use Lightroom 3 and print with an Epson 3880. Lightroom 3 automatically interpolates the image, and I do not need to apply resolution dpi because Lightroom does this automatically too. On the Epson, I match unique profiles that match different media i.e. for each printing paper there is a unique profile on the printer. You should have this on your printer too I'm assuming. Anyway, the profiles make sure the colors match and that the print looks good on the media's surface. All of the above apply to produce stunning prints. Now if you don't have Lightroom 3 you might want to look at some other software that can help "upsize" the photo. Lucky for me, there is no guesswork as Lightroom auto applies this for me, and streamlines the workflow. Another major thing you really need to consider before printing is to make sure you have zero noise and artifacts in the photo, because these will be highly pronounced when you enlarge the pic. SO make sure you have some type of basic editing software to eliminate the noise etc. Btw, are you sure you can print the above A1 size? You'd need a large format printer that costs bare minimum 2,000$. If you can't, then send it to the lab! They can! And finally, if your printer is able to print the photo and you don't necessarily trust yourself, then try sending it to the lab and printing it yourself and compare and contrast the two. See which one you like more. Some labs will have media that you might not be able to get, and sizes you wont be able to print. And like everything photographically or like anything in life, try as many thing as possible, test them, then compare the results and go with what you like more. Simple right?!