Going to Grandma and Grandpa's

Gracie and I went to finish getting her passport Friday since she will be going to Grandma and Grandpa Ski's next month! We will be leaving Tuesday February 17 and arriving on the 18th in Manchester, England and staying in Derby. Fortunately, we will be getting to stay for about a month. Grace and I are too excited!! For all my mothers out there, any ideas on how to travel with a baby, especially internationally? I've read several sites and have gotten some great information, but more is always appreciated.