I'm new to this, so I may get this wrong. I'm describing this for the USA only.
I used Google Earth to make my maps. There are no ready made maps for the US in POSFIX that I know of so even if you want to use it, you still have to make a map(s).
The reason that I used Google Earth was because Google Maps, Mapquest, Yahoo Maps, etc. was not very good when it came to accurate latitude/longtitude plotting.
If you need to bone up on what latitude and longitude is, then look at this page:
http://www.boatsafe.com/kids/mercator.htm It's for kids, but that's good because it doesn't assume very much.
First, you have to know where you are in latitude and longitude. Here is a link to tell you.
http://world.maporama.com/idl/maporama/ Type your street address in there (don't forget the city) and it will plot pretty close and tell you your lat and long in the lower left corner.
Then start Google Earth and zero in on your house. First you want to turn on latitude and longitude lines, View | Lat/Long grid. Then set a new placemark on your home Add | Placemark and type in your lat/long the website gave you.
Right away, you see that there is a problem. There are two ways of expressing latitude and longitude. In this Google Earth you will see it expressed in N and W analog (Degrees Minutes Seconds -- 60 minutes in a Degree, 60 seconds in a minute) and Acarsd uses digital (Degrees minutesseconds -- 6 minutes in a tenth of a degree) if you need help converting these, then look at this page:
http://www.fcc.gov/mb/audio/bickel/DDDMMSS-decimal.html
The biggest thing to remember about digital method of lat/long is that West is expressed as a negative number. If you use a positive number, you end up on the other side of the world. Here is an example from the kids page I mentioned above. New York is roughly 41 (degrees symbol) North of the equator and 74 (degree symbol) West of zero degrees. So in analog we would say 41N-74W and in decimal or digital we would say 41.0000 (degree symbol) -74.0000 (degree symbol).
Now that you have a placemark in Google Earth, make the area as large as you want it to be, plus more if you have to straighten the image very much. Using the layers, add roads, airports, whatever you want. I try to keep mine simple. then save the image File | Save Image. Don't close Google Earth. You will be back.
Open the file in a drawing program -- MS Draw included in Windows will do in a pinch -- and rotate and select what you want, cropping out what you don't want. Study the lat/long grid and try to follow the lines when you select the area you want to have. Write down the lat and long of each corner. Notice that the degrees are expressed as 30 or 15 minutes and in digital form that would be .5000 and .2500. Try to make the image square.
Save the file as a GIF file called card1.gif in the /acarsd65 folder. You should be able to see it when you open the first map. Now you have to enter the corner points in acarsd. Don't forget the negative sign. Then add where you are (using the lat/long from the website).
If you are like me you may mistype a number (or more than one). First goal is to see the "Your Server" stick pin on the map. If you can't see it, check the numbers again. Chances are that you mistyped. If you can see it, but the two stickpins are not very close, then look hard at the corners again. Refer to Google Earth again and make sure that you didn't type in .15 for 15 minutes or .30 for 30 minutes.
I know that this sounds hard, but after you have made your first one, it gets much easier
I think where some people get confused is that they expect to open the map and see it populated. The map has to be open before the message comes in. I have noticed that most planes around here don't give out any position messages. So leave the map open for a while and then look. Don't be surprised if you don't see anything.
