Depends on the department and state. Here, most reserves are unpaid volunteers, although the department pays for their uniform and some equipment. Some departments do pay their reserves, however. Our reserves come out to work and supplement the full time officers. They have the same academy training, and are able to work by themselves after passing a probationary period. They are required to work a minimum # of hours each month, and pretty much make their own schedules except for a couple of mandatory events such as the county fair and parades, meetings and trainings. Our department policy doesn't give reserves off duty authority, which is one more difference. Could be totally different in your state, however.
"The inherent vice of capitalism is the uneven division of blessings, while the inherent virtue of socialism is the equal division of misery." - Sir Winston Churchill