Part 1: Modeling the Nissan R390 GT in 3ds max 5
>> Section 1: Before we start with the serious stuff
The very first step is finding as many reference images as possible. Any search engine is ok, I personally use http://images.google.com/
a lot to find good images (the advanced search function lets you restrict the search to only mid to big size images). Then you obviously need some good blueprints: more and more sites are offering this stuff, I won't list them here.
Fig. 1: setting up blueprints is pretty easy - be as precise as you can
Once you are satisfied with your references and got blueprints, you have to cut and resize the latter so they represent the car in the correct scale (many times i found different blueprint views don't match properly, so you have to resize them accordgingly). That's easy enough.
Now it's time to put the blueprints in 3ds max's viewports. Open max, create 4 planes using the pixel dimensions of your blueprints as references (you can scale the planes later if you want), align them properly and assign them the maps (just make surem you click on "Show map in viewport" in the material editor). Everything should be self explanatory from Fig. 1 above.
As I said, you should also scale the planes (all together) so that they match the real lenght/height of the car, in the units you are using (I usually use cm., but it really doesn't matter that much if you're not goin to use radiosity). You can move the front and back plane wherever you want on the lenght axis, to help you in the modeling phase.
Next I always right click on the bottom-right viewport icons to open up the option menu, and check "default lighting", "2 lights" and set the transparency to "best".
This concludes the easiest part, now we can move on to something more interesting.