You should be able to get a simple map from the company that you rent your car from. Also, if you are a
AAA member, just stop by your local office and ask for a FL map.
To get around property, if you are staying on-site you can get a map from guest services at your resort. However, I have found that the best way to get around WDW property is:
1) Know which park, the resort that I want to go to is near
2) Follow the road signs on property.
For example, if you want to go to a MK area resort, then when you leave your resort, follow the road signs to the MK. Once you get closer to the MK, you will see signs for the resorts near the park.
I have found that the WDW road system is well signed.