When you get here you'll have the opportunity to get many free maps of the centre of Prague. This map will help you get a bit more familiar with the centre. If you have a PayPal account this website sells a pre-travel kit which includes a nice Prague map. Details are on the Headstart Kit page.
Click on the picture of the Prague map above to be taken to the full size Prague map version. Beware that even at reduced size the Prague map is still more than 600k so as to make it better for viewing and printing. When the next window appears, place your cursor over the Prague map picture and wait for the expansion symbol in the bottom right hand corner of the picture (square with arrows).Click on this symbol to expand your Prague map to full size. The Prague map covers the main tourist area from Hradcany in the top left to the New Town bottom right. For detail it still does not match the Prague map resource at mapy.cz for which the How to guide to mapy.cz was written. This also has aerial Prague map view options that I show you how to use.