However, for any flight over 4-5 hours, consider Business Class instead of Economy. The difference in your physical and mental alertness will more than repay your company for the significant difference in cost. Not all airlines allow advance seat selection. Ask your travel agent. On those airlines that don't reserve seating in advance, it is well worth your efforts to arrive early.
Lodging is a very personal choice.
Many American business travelers play it safe and use only well known American chain hotels. Other travelers will research each destination city to identify the better hotels at each location. An advantage of doing a little advance research is that you will get an idea of the price ranges in each city. Many destination cities cover a very wide area, always contact your colleague in each city, and ask them to recommend a choice of several hotels and advise you of their rates and locations. In some cities, it is less expensive to book your room through your local colleague.