How can I make a log for caregivers/sitters to sign in and out?

If you aren't a computer person, find someone who is and have them make you exactly what you want. There are all kinds of things a person can do with Microsoft Word these days.

Or, the "computer person" can download OpenOffice, it's a free full-featured office software suite, compatble with Microsoft Offce. Then go to http://www.vertex42.com/ExcelTemplates/Images/visitor-sign-in-out-sheet.gif , where the sign-in/sign out sheet can be printed from OpenOffice, or from Microsoft Excel (.xls file) or Adobe Acrobat (.pdf file).