IM is built into AOL's software, so it starts automatically when an AOL user connects to the Internet. You'll need to register a screen name for yourself to use with the Instant Messenger software, but after that it works the same way. IM isn't the only program of this type available on the Internet. Each of these programs works in basically the same way. These computers let you know if the people on your buddy list are connected and available, and they'll let others know if you're available.
Messaging is simple and secure.
All of these programs are free to download and use. Some, like IM, cover the cost of the system by selling advertising, but the ads are unobtrusive and can be hidden by simply minimizing the program. All the programs have pretty complete instructions for setup and registration, so none should be too difficult even for the very greenest of newbies. That probably depends on where most of your online associates and students are hanging their hats. Ask around at family gatherings or pass out a sheet of paper at youth meetings and ask students to give you their e-mail addresses.