How to import boat plans (tif images) into autocad??

Here is the story:
1. I have ordered some boat plans (hard copy). Some plans are even 9 feet long. 2. A company has been so kind and scanned all the plans as tif-images. The scans are exactly 1:1. 3. Somewhere on the internet I have read that you can import a tif-image, make it as a layer and then draw upon the lines you see from the image making a real autocad file.
But how can I do that? Do I have to use the imageattach command (I have Autocad 2004) and then import the image like that? It is EXTREMELY important that the image stays 1:1 in Autocad. How do I turn the image into a layer? Maybe someone has some advice? Im still a beginner using autocad :-)
Reagrds, Lucas Jensen

insert as raster image.. then scale if necessary
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Use the IMAGE command. Then SCALE the image using the Reference option against a known distance in the image. ___

I always need to adjust the image as well. Use "imageadjust" and change the Fade slider untill its transparent enough for u to trace over it.
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Hi You don't need to think about scale , do that as the last thing when all lines are digitized .

A further refinement might be: after you get it scaled nicely, turn IMAGEFRAME off to keep from accidentally moving the image. Put the image on it's own layer so you can be turned off as needed.