He could use Quickbooks. They have software and a service online for a monthly fee, but this might be more than what he's looking to do.
Leo would suggest Mint from Intuit. It's free online, and instead of entering all the data himself, he would connect this to all of his accounts. It's completely safe to use because it uses the same backend service that all of the major banks use, Yodlee. So they have all of his banking information already anyway.