I have a photo of dimensions 1200 x 1600 px
How do I get it to print on A4? Every time I try it prints much bigger.
Open a new document window using the dimensions and resolution you see in the image below. Note that if you know the native resolution of the image, use that instead of 300 ppi.
Once you've done that, import your image into it. You'll be asked to choose whether or not you want the image resampled to a new resolution. Choose yes and try printing it. Fireworks was never designed to be a print graphics application, so you'll need to experiment a bit to get the look you want. Here's an article you might find useful. http://www.communitymx.com/content/article.cfm?cid=FDC30