People are always surprised when they see a McDonalds for the first time in Thailand. I don't know why, but maybe they think it is strange to see something "modern" in an Asian country. I think most tourists who come to Thailand want to taste the famous Thai cusine. But, I understand that if they are here for a week or more it is nice to have something familiar. Many of my Thai friends take suitcases full of mama noodles whenever they go abroad on holiday!
Really, you don't need to worry about speaking Thai in the McDonalds restaurants as in most tourist locations the employees will be able to speak English. Also, you will see that the menus above the counter are in English and Thai. However, away from the tourist centres you will find that not much English is spoken and the menus are only in Thai.
In Bangkok, have a go at ordering your food in Thai and if you get stuck don't worry. They will help you out in English! Then, when you go up-country you can practise your new language skills.
(Primary 6 students from Sriwittayapaknam school were asked to write bilingual conversations for someone who wanted to eat at McDonalds.)
The following are the books on our "essential reading" list.