The first thing, what you have to do is to estimate how many users will be interested in local R group. I would say, that out of one million inhabitants you can expect 10-20 users. Based on this raw number, you can know, what challenges are waiting for you. If you expect 100 or more users, you have to think about the appropriate place to hold first meetup, how to manage so many people, what topics to present first time.
However, if you expect small community (as I did), your challenge is spreading the news about local R group. Get to know a few local users and ask them, what do they think about a meetup. The right place to find such users would be local university. Most likely the local university will be happy to provide a place for the first official meeting.

Fortunately for me, I met a powerful R user – @mpiktas, which is a lecturer at Vilnius University. With his help I was able to identify more R-infected users and get premises at university for presentation.

Next step, when you are sure, that you are not alone, is to choose a name for the group, build simple web site from scratch or by using a service like meetup. This won’t cost you a fortune, however I need to say, that you can apply for sponsorship. Revolution Analytics not only provides sponsorship, but as well manages a dictionary of R user group.

Once you have created virtual community you have to thinking about a meetup. As a founder, prepare an introduction about local R group, its future plans, your own usage of R. Here mine, which I used for VilniusR introduction:

What’s next? During first meetup you can outline future meetup, however I found fascinating, that many participants expressed an interest in datadive event. So, now we are in the process of organizing such event!

p.s. if you happen to be from Luxembourg and you are interested in local user group – let me know.