The key to a successful group is making every possible effort to come up with solutions that are supported by the majority of its members, through principled compromise and developing alternative solutions. Someone who feels like their view is respected will come back again. If you operate by vote, consider requiring a two-thirds majority for approval. This way you will be forced to come up with a plan that at least most people are happy with. Not everything can or should be decided at meetings, however.
Email lists are a great way to keep people in touch and up to date.
You can just send an email to everyone in the group and have people 'reply to all', but you might prefer to talk to the computer center at your school about setting up a mailing list. Don't be paranoid, and most of the time it won't matter, but for some action plans you may want to lay low. Though your group may or may not have official positions, you will still need to delegate responsibility to get things done. If you try to work out every detail in a meeting you'll be there forever. Come up with a general plan and then have someone or a small group take over.