Help with mother-in-law relationship?

My husband and I have been married for 4 years and my relationship with my mother in law is strained at best. My inlaws didn't come to our wedding and things were really bad for several years. Things began to improve after our son was born 2 1/2 years ago. Every time I think we're starting to get along, she says something insulting or insensitive to me. Part of the problem is a language barrier. She is fluent in English, but it's not her first language, and sometimes things get lost in translation. I would really like to improve our relationship, but I don't know how to go about it. She's a very selfish person, and she doesn't even look out for her son's best interest at times and that frustrates me. She's not the type of person I can have a deep meaningful talk with. I'm wondering if I should get her a book about mother-in-laws and daughter-in-laws. I've looked at some good books, but I'm worried that she will take it as an insult if I give her a book like that. I really don't know what to do, and any advice would be greatly appreciated!