Forget TurboTax for a bit; you may not even need it, and for simple returns, paper forms are pretty easy. If your income was low and you meet certain criteria, you may be able to use the 'free fillable forms' or one of the free file services.
First of all, have you been working in the UK? And do you have bank accounts in the UK earning any interest? Are you married? Any dependent children that you can claim?
If your ONLY income was in the US from Jan-April, it's no more difficult than filing any other year. The federal return is the federal return - it's not a 'part year resident'. Your state return might be, depending on the state.
Folks will provide more answers I'm sure, but not without specific information on your situation.