I'm taking my Thai wife to the States for a few weeks in October. We'll be staying with my folks. I realize I need a letter from home but I'm not sure what info is required. Can anyone give me a checklist of what I should ask for?

Thanks

You don't need a letter from home but it could add to the documents that you do present.

She needs to have a non immigrant visa to travel to the US and some information can be found on the Embassy web site. In general she needs the same type of information any visitor would need but perhaps the most important thing will be your status as living outside the US and thus she will be expected to leave the US. Letters from home as part of the process can be used as reason for visit and such. If her money and yours will not meet expected expenses the letter could explain how trip/accommodations are going to be provided.

Remember the primary concern is that she has the money to travel and will leave at the end of the stay. Being married to a US citizen they will be concerned that this is not a fast way to enter the country and adjust status later so your ties overseas can help reduce that concern. And do start early.