Robert's Rules says that if you expect to do business in the name of a group, then every voting member has a right to previous notice of the meeting. It's easy to understand why: If you have a right to vote, then you have a fundamental right to attend. And you can't attend a meeting if you don't know about it, right? And if your group is a public body, like a school board or a town council, then you probably face some legal requirement for public notice, too.
As a voting member of an organization, your notice of a meeting should contain information about the time and location of the meeting as well as specify all items of business that require previous notice under your rules. Common examples of such special items of business include proposals to amend bylaws, to adopt or amend special rules of order, or to amend or rescind something previously adopted.
The type of notice you must give depends partly on what type of meeting you're giving notice of:
Regular meetings are regularly scheduled and open for any regular business that needs to be discussed. The content and the delivery requirements of the notice for regular meetings depend mostly on the details of scheduling already contained in your bylaws, which should also provide specifics about when and how meeting notices are given. The lead time always should take into account the frequency and importance of a particular meeting and the distance members have to travel to attend. Give notice far enough in advance for voting members to receive the notice and arrange their schedules so they can attend.
Special meetings are called only if something important comes up that must be dealt with before the next regular meeting. Special meetings always require previous notice. Special meeting notices must include not only the date, time, place, and location, but they also must specify all the business to be included in the meeting. Nothing, repeat nothing, can be considered in a special meeting if it's not included in the notice.
To be on the safe side, make sure your bylaws state that written notice of a special meeting must be mailed within a specified time frame before the meeting. For example, "Notice of special meetings shall be mailed to the members at least 14 days but no more than 30 days before the meeting." The actual range for notice will vary depending on the size of your group and the distance members must travel.
Depending on the rules of the organization, previous notice can take any of several forms. Meeting notices can be given
By a simple announcement at a regular meeting. Small informal committees that meet frequently to work on a project often adopt this method.
By a fixed rule in the bylaws establishing a regular meeting time and place. For example, "Regular meetings of the Second Thursday Club will be held on the third Wednesday of every month, at noon in Tuesday's restaurant."
By mailing (or otherwise distributing) written notice of the time and place of the meeting a reasonable time in advance. This is the most common method.
Be aware that electronic notification often does not fulfill the requirement to make a good faith effort to contact your membership as some members may not have easy access to electronic communications.