Because every tank is different, there are no hard fast rules for most maintenance. Here are a few rough guidelines.
Partial water changes at 10% per week or 25% per month.
Mechanical filter media cleaned once a week, and replaced when it no longer can be cleaned.
Skimmer cup as needed, usually once every week or so.
Internal pump parts 2 to 4 times a year.
Chemical media replaced as needed.
Cleaning the front glass, tank cover, as needed.
Fluorescent bulbs every 12 to 18 months.
Mucking out the sandbed and live rock, once or twice a year.
Remember these are very rough guidelines. Some systems need more frequent cleanings others need cleaning far less often. As you go along you'll find out what needs to be done for your individual tank.