My wife received a 1099 misc. from a group memory impairment study she is in. she was told the money was for transportation expenses. How should I enter this on my taxes?

I assume box 3 is where the income is reported - as other income. Other income is taxable but not subject to self-employment tax. 

Take the following steps:  

1. Sign in to TurboTax Online, click Continue your return, then pick up where I left off (if you are using TurboTax CD/ Download, then just open your return on your computer); 
2. Click on Federal Taxes at the top of the screen; 
3. Scroll down the page to the last section titled: Other Common Income and click show more; 
4. Select start or update next to the topic titled Form 1099-Misc; 
5. Answer Yes, to the questions Did you get a 1099-Misc? 
6. Enter the information from your 1099-Misc. 
7. Enter medical study for the reason for the 1099-Misc 
8. None of the uncommon situations will probably apply, and if so, you can click None of these apply 
9. Select No, it didn't involve work that's like your main job. 
10. Indicate how often you get this income. 
11. Select No; the medical study did not involve an intent to earn money. 

This will add the income to your 1040 form.  Again, the income will be subject to income tax but not self-employment tax.