Applications that make carbonless copies should always be typed. Attach resumes and other materials only if they are specifically requested. Early Action means that your application will be reviewed during an earlier timetable than the bulk of the applications to be submitted. Decisions are usually made by December with offers of admission, denial, or deferments until later in the spring. You must sign an agreement with your application that commits you to attend said school and withdraw all other applications should you be admitted early.
Early action is definitely the rising trend.
If you have completed a rigorous program of academics prior to your junior year, then you are probably ready to apply for an early decision. However, at many schools, students are unable to take advanced or AP courses until their senior year. Students in this situation may want to submit applications under the regular-admission timeline. I suggest you have all applications ready for mailing by December 15th of your senior year and submit these before you depart school for Winter Holiday. The Schools will appreciate your diligence.