England's Perfect Hero by Suzanne Enoch

Lucinda Barrett's best friends ended up married to the men to whom they delivered their 'lessons in love'. So Lucinda decides to choose someone who definitely needs lessons, but someone who will not complicate her life. And that person is definitely not Robert Carroway.

Robert is nothing if not complicated, and though he is the brother of a viscount, he rarely goes about society, and finds the weather and hat fashions ludicrous subjects for discussion. Robert is attracted to Lucinda's unpretentious ways, her serenity and her kindness. When she chooses someone for her love lessons, Robert offers to help her deliver her lessons, but sets out to convince the woman he has fallen for to take a chance on love ... and on him.