Let's try to setup for a Landclass for the Plaridel Area
Step 1. Make the Reference map.
1.1 In FS I go to the approximate center of the area I want to work on. I note the Latitude and Longitude of that area.
This is the top down view of Plaridel with the aircraft on the Runway.
1.2 In Airport for Windows or AFW (I think you can do the same in FSSC) I create a very long runway at the lat-lon above. AFW can display the current airplane position if FS so it is possible to locate the runway this way without having to note down the lat-lon.
Runway length could be at least 10,000 meters (10 KM) depending on the size of the area you are working, but I think 10km is workable enough.
Make Runway heading 135 deg magnetic.
1.3 Back in FS I go to Top-Down view (Ctrl-S)
This is the 10 km x 500 meter runway over Plaridel.
1.4 I slew to the NW end of the runway and take note of the lat-lon of that point.
1.5 I then slew to SE end of the runway and again note down the lat-lon of that point.
1.6 I move back to the center of the runway and zoom out to a height that will still give me enough detail of the default terrain. About 15 miles Altitude on the View Options window.
1.7 I make a screen capture (Alt-PrntScrn) and paste the image to my graphics editor (I use Paintshop Pro 7.0 but any grpahics editor will do). This is somewhat similar to the screenie above.
1.8 I go back to FS and make additional screen capture with airplane located on adjacent areas. I take care that the zoom out altitude is not changed from the first screenie.
1.9 I add these adjacent areas screenies to the first one (with the runway at the middle)
1.10 I repeat steps 1.7 to 1.9 (taking care that the zoom out in top-down view is not changed) until I get an area that is as large as the area need to work on. Experts suggest that this area be kept down to a maximum of 4000 x 4000 pixels for performance. So you may limit the area you are working to this image size and create another reference image for the adjacent area until your whole project is covered.
You will get something like this for Plaridel. This is resized to fit in the page but it is a big bitmap.
1.11 Save the image as a bmp file, e.g. Plaridel_G2k4.bmp.