How should I deal with my new in laws when I go back?

Hi All,
I have been away from my parents and sister for 5 years because of my work and finally I have decided to go back to my country and continue my career there. But during the past five years my sister met a guy and now they are getting married next year thus providing a whole lot of to be in laws when I get back home. I hardly know any of these new people and I do not know how one should deal with them and specially my to be brother in law. I believe I am an okay guy and a friend but my sister never had a bf before so I am totally lost how to handle such situation So if anyone can provide some help that'd be great.

be friendly. changes and routines are difficult. change doesn't have to throw you into a panic. plan, decide, and act, based upon being the objective realist as opposed to the romanto-intellectualist. change is a part of life. you may want to even look for a room or apartment of your own, since you're accustomed to and seem to value your privacy and independence. be group-minded instead of self-led. objectivity terminates panic. if you have to stay there, get involved in cleaning or maintaining the living space somehow. remember that this is perhaps distressing but certainly not dangerous. you aren't going to iraq or to some penetentiary. plus, even though you may think it is, it's temporary and not permanent.