Markus, try the attached example map. It's setup with control points and you can press the Register button to make the magic happen. I use Vancouver BC as the example map (making a pitch for a future Manifold user's meeting, ahem).
To get the workspace layout shown in the attached screen shot, open the two images in the .map file: a) Vancouver BC georeferenced basemap UTM9 (a georefernced TIFF image) and b) Non-georeferenced image which was a screen shot from Google maps. The georeferenced basemap is the reference to which the non-georegistered image will be stretched to match. To get the same layout as in the screenshot, click on image Vancouver BC Georeferenced basemap to give it the focus. Then on the menu, click Window > Tile vertically. You should have what the screenshot shows, georeferenced on the left, non-georeferenced on the right as in the screenshot.
With the View > Panes >Control points pane active, you should see the five control points I've already made. You can add other control points. It doesn't matter which image you start with. Pick a prominent landmark that appears in both images. In this instance I used points of islands, where major highways have a corner, where there are unambiguous intersections, whatever I can find that's unambiguous. There is a correspondence between control points between the non-georeferenced image and the georeferenced basemap component. Create a control point in one image and create a corresponding control point in the other image. The incoming non-georeferenced image will be stretched until its control points coincide with the control points on the reference map. I find about 4-5 well distributed control points is sufficient but go ahead and add some more to try it out.
Do the magic. Click on the non-georeferenced image to give it the focus. In the control panel pane, click on the Register icon. In the Register dialog box, confirm that the reference is the georeferenced basemap. Click OK to register the Google map screenshot.
Create a map of the two images, make the just-georeferenced map the top layer, it should lie correctly over the basemap.
If you have a drawing made from a table of points, you'll need to be able to find and make control points in the incoming JPEG image that match the points from your table. Sometimes this is not easy. Sometimes I have surveyor's drawings that are over 100 years old that do not have modern roads and any rivers have changed their channels. In that case there are very few common points between the incoming image and my georeferenced map.
Example of georeferencing.map
Screenshot of georeferencing.JPG