I would second the fact that you need to be careful with a company like GM. If you don't have the experience, you probably shouldn't be getting into individual stocks. Unless you have a whole lot of extra cash, then go for it. Have fun with it. Otherwise, you should play it a bit more safe and purchase mutual funds.
Also, someone earlier mentioned disability insurance. That is absolutely huge in financial planning. Get some and get it from a VERY good insurer. There are probably only 3 companies that you should buy a policy from. Also don't think that just because you have a policy through work that you have enough. Most policies at work are for 60% of your income. Then that will most likely be taxed at regular income rates. So you are looking at less than half of your current income. Not many of us could get by on half of our income.