Leslie,
If you have Beta 2 of 10.1, I found that you can just go to the labeling toolbar, click the Labeling button and then select, Use Maplex Engine. I guess they took Maplex out of the Extensions since it now works on all the products.
You can make Maplex the label engine by default by going to Customize|ArcMap Options, click the Data View tab and then select Maplex Label Engine under Label Engine.
Hope that helps.