Casey,
...and my score is 600 at last check...
How long has it been since you checked your credit? The first thing I would do would be to order a tri-merge credit report with 3 credit scores to see what's on your file. The report should explain what is driving your scores and offer suggestions to improve your score.
Your credit score is made up of several components including: payment history (35%), amounts owed (30%), length of credit history (15%), new credit (10%) and types of credit (10%). It's possible to have a relatively low score and not have any late payments if you are using a high percentage of your available credit or if you have little credit, or a short credit history. Check out the MyFICO (dot) com website and search for "What's in your FICO score" for an explanation of how credit scores are determined.
I haven't had a credit card since college 8 years ago...
I think mortgage lenders want to see a minimum of 4 lines of credit, so you need to start establishing credit. Gas cards and department store cards are fairly easy to get. I've heard a couple of strategies here. One is to payoff your balance every month. The second is to leave a small balance and pay it off over several months. I don't know which method is the best. I think you want to maintain any balances under 30% of your available credit and never more than 50%.
I want to buy a home one day is my intention.
It's possible to buy a house without using your credit or going to a bank. You can buy using seller financing or you can buy "subject to" the existing financing. So find yourself a motivated seller and see if they will carry back owner financing or if you can take over their payments.
There should be several articles/posts on BP about these methods of buying that don't require you to have good credit.
Good Luck!
wade