Survey your family, friends, and co-workers to determine who would be interested in starting a weekly or monthly film club. The only real rule is that members either agree to rotate at each other's houses or attend movies as a group, and then meet somewhere afterwards to talk about the experience. If the cost of theater admissions and concession food is too high, you can opt for getting together in private homes, renting selected movies, and bringing your own snacks.
Determine how often your group wants to meet. This, of course, is dependent upon how many other things your fellow movie lovers have going on in their lives. It should also be stressed that members don't have to attend every showing. If, for instance, you decide to communicate with one another via email or phone, you can announce what movie will be "playing" at the upcoming session, and they can RSVP as to whether it's a film that interests them. If it's a small group, you can easily operate on a rotational basis wherein each member gets to pick the next movie at the same time you decide who will be the host.
Decide where your movies are going to come from. You might want to start out with members bringing favorite movies from their home collections. Once you have exhausted that supply, you can then move into determining whether you want to rent videos and DVDs from sources such as NetFlix and Blockbuster. If only one member of your group has an existing account at these venues, you may want to consider everyone chipping in to help pay for the movie rentals. Depending on the size of the group, a donation of 25 cents to $1 is pretty cheap compared to what you'd individually be paying to see all of these films at a movie theater, which can be around $10 each.
Respect one another's tastes in movies. While a film club is a good way to expose yourself to films and genres you might not ordinarily see on your own, no one should be forced to watch something they don't like. Nor should the same person always pick the movies unless it has been decided beforehand that the group only wants to see films of a specific genre, the works of a specific director, the movies of a specific decade, or any other unifying theme that grants the decision maker a lot of latitude.
Decide how you want to handle food and drink. This can range from the host providing the refreshments each time the club meets at his house, each member contributing a potluck item, each member "brown bagging" her own meal and beverage, or the host picking up takeout food and being reimbursed by the other members. The key is to keep things simple and inexpensive for all of the participants. You can even have a standard popcorn/soda/beer menu that will keep everyone happy while they settle in to watch the new flick.
Allow an hour for discussion after the movie is over. This is where everyone gets a chance to express an opinion on what they liked, what they didn't like, and how the movie compares to other films they have seen. The objective here is to allow each member the chance to speak and to be politely listened to by everyone else. If everyone starts talking at once, or if the discussion is constantly "hogged" by one or two members, interest will quickly drop off and the club will unravel.