Most definitely, read 5LLs. It doesn't presume the sexes have one love language over the other. Many books I've read assume the "male" language is usually Physical Touch and the "female" language is Acts of Service. I hate those presumptions, because in my sitch, it is the opposite, and it has been a source of ongoing marital conflict.
You can also take away from these principals relating skills for ALL relationships, such as children, parents, co-workers, etc. I haven't read HNHN yet, but I don't think you'll find this reading redundant.
