Newbie about to get in too deep - What are major check points for 1980 450sl?

[supercanuck]

I have a 1980 450sl that I am about to turn into my project car. I know very little about cars, but figure this is the best way to learn, right? The car has been sitting for a year or so, and was only run every once in a while. I have been working on little things like the instrument panel, etc etc, but I am more concerned about some of the bigger problems, issues the cars have.

What are some of the major things I should look at in the car to determine whether or not they need to be fixed/replaced that could cause major problems if not addressed? I'd like to eventually get to everythign in the car, but what areas should I focus on first to make sure they are good before I get too far?

ANY advice is appreciated!

Thanks!
Zack