Access 2003 Small Job

I have a very basic database for tracking plant and equipment. It is one main form with 3 popup forms activated by control buttons. 1. On the main form i have 4 textboxes for entering the current date, hire date, reminder date and return date. What I would like is when I click on the textbox a popup calendar appears and the user picks a date and the date shows in the textbox. 2. I would like when the current date matches the reminder date it sends an email to advise that the plant & equipment are due for off hire. I would like the database to automatically turn on when the user turns on the computer and run in the back ground. 3. If i open the main form again I can select a project number from the combobox and be able to access the reminder date to extend the reminder date and then save the new date.