You generally want to schedule speakers 3-6 months in advance. In addition to the schedule, you should also have a short list of people you know well who can be asked to fill in on short notice if one of the planned speakers cancels for some reason. If possible, you also want an absolute disaster plan, for how you're going to fill time if a speaker is horrifically late or fails to show on the day of the event. Appendix B lists some topics that existing local groups have used, but you'll need to brainstorm to fit the speakers you have available and the interests of your members. Picking topics and sweet-talking speakers should be the number one priority of the group's organizers.
Many local groups have events besides regular, topic oriented meetings.
Most local groups run mailing lists, which often become sources of information in their own right. T-shirts are also popular, and easy to do. Newsletters are popular with members, and provide you something to show other people, but very difficult to get out on a regular basis and relatively expensive. You may get higher attendance by staying in a poor location than by switching locations often. This does not hold for groups that intentionally meet in a different place every time, but even they should be careful that the meeting day is consistent.