That's great news that you have found a house sitter in time for your departure!
Please find below a link to our house sitting agreement. Generally, our advice is that you should meet with your house sitter first before agreeing to the assignment. During this meeting, you should go through the house sitting agreement with them, so that your (and their) expectations are met and agreed upon.
If your house sitter is coming from overseas and is unable to meet with you, you can arrange to meet online (eg. Skype) although this may be a bit harder.
In addition, we also have a checklist for home owners, which you may find useful:
We hope this helps.