Provide a car for the spouse.
Give information on schools, busing, libraries, etc.before they leave for the assignment.
Give contact names of good doctors, dentists, etc.
Provide language lessons.
Contact information of other expatriates in the area.
Our expats are exclusively in Japan. We provide the employee and his/her family with two-months of training to help them learn about the cultural differences, pick up a few language basics, and provide them with basic geographical knowledge (locations, schools, markets, etc.). We try to place all our expats close to one another so they don't feel overwhelmed being in a new country alone.
My sister-in-law was in France for 12 years when her husband was an expat for a mega-famous US company. Luckily, there were others from the company posted in Paris, so there was an instant "community" to guide them along the first few months. And the company sponsored events like picnics and parties for this group.
The company gave them extensive language training (Berlitz) before the move; however, these courses just don't cover the words you need in everyday life, so they pretty much walked around with a translation guide for a year. Of course, the children picked the language up immediately and are completely bilingual.
She told me the most helpful thing was the free trip home each summer for the family so they could do dentists' appointments, school shopping, and visit relatives.