Having to start somewhere, I am going to assume that you own a digital slr already and that you know how to take pictures with it. Your task then becomes the following: 1. Couple the camera to a Telescope 2. Aim the Telescope at the object you want to photograph.

Keep the telescope aimed at the object with the precision necessary to produce a sharp image for the duration of the exposure. To accomplish the above, you need to become familiar enough with the night sky to find the objects you want to take a picture of. Very easy in the case of the Moon and most planets. Not easy at all in the case of most galaxies and Nebulae.

You will also find that some facets of Photography are different from terrestrial photography. Getting the right exposure time is easy while focusing is one of the most difficult tasks of astro imaging. Exposures of several seconds are possible to image the star fields of the Milky way, for example. Images of star trails with exposure lengths going into hours is also fascinating. With a telephoto lens you can take some very nice pictures of the whole Moon, since exposure times are short, no guiding is necessary. Once you get past this point however, some kind of a tracking mount is needed, along with a Telescope.

Now comes an important decision point. In general terms, the bigger the telescope used for imaging, the better and more accurate the mount has to be.

Remember, when you increase the magnification of an image, you also magnify any errors to the same extent. Many folks find it easier to start with a short focal length Telescope which requires less accuracy from the mount and upgrade their equipment as they gain experience. Starting with a big, long focal length Telescope and the mount to handle it is expensive and can be very frustrating, with a super steep learning curve. Autoguiding must be used to correct the pointing of the mount during the exposure. Let me make something very, very clear: For Astrphotography, the Mount is the single most important part of the whole setup.

And we havent even talked about dedicated Astro Cameras yet where the imaging chip is cooled to reduce electronic noise. Along with a very good quality mount. If you are sure that you will keep upgrading your setup, get the correct mount for the Largest scope you anticipate using later on. Objects as your favourite targets and you would get a Telescope specially suited for that type of imaging. One thing in your favour is that good Astronomical equipment maintains its value quite well, should you change your mind and go in a different direction. Tons of info is there for you. Revisit times by commercial imaging satellites such as Ikonos are about 3 days, and it would take many weeks of collection to map the entire US.

With the other demands on the bird, you will not find maps of an arbitrary locations in the US consistently that are less than 30 days old anywhere. Page 12 of this product guide instructs you how to contact GeoEye to request a quotation on a custom product.

Philippe Druillet is always good for that kind of stuff. Jack Gaughan is a favorite.

Here is the closest you will get to live. These are updated every few hours. Google Earth, Terraserver, and Live Local are all using satellite imagery that is up to several years old, and they reduce the resolution for areas outside of large cities.