As others have said, track your budget so you know where your money is going.
Past that, start investing in your retirement. I strongly advise reading this thread over at SA: http://forums.somethingawful.com/showthread.php?threadid=289...
In summary:
1) Contribute to 401(k) up to employer match. Employer match = free money. There is not a single investment that has a greater return on investment than your employer match...even if the 401k has shitty fees and shitty funds.
2) Max out Roth IRA (or possibly traditional IRA if you are in a high tax bracket)
3) Max out 401(k) - optional step, depends highly on your 401k plan. If the plan is good, this is a great place to shelter tax-advantaged dollars. If your plan is bad (high fees, etc) you may be better off just using your money in step 4
4) Start a taxable savings account, brokerage account, or go out and blow some money at a strip club or something.
That's all retirement savings. You should also divert money towards long-term, non-tax-advantage funds. This is something that you want to put money in and gain more than 1% interest in a bank account, but may need to liquidate before you retire (purchasing a house, going on a trip, etc)
Edit: Also, if you ever have the desire to purchase individual stocks - stop and invest in an index fund. If you accept that you will never beat the market (which in all likelihood you won't, especially if you don't have time to research stocks), you should never purchase individual stocks as a means to make money.
Now, I purchase a few individual stocks on the side, but this is my equivalent to gambling or buying lottery tickets. All the money that is set aside for retirement or long-term investing is firmly placed inside of index funds.