Questions about hiring a remote dev

Hi guys.

I wanted to get a remote dev to help me work on a new SaaS prodcut. I don't have much experience with hiring remote devs before. so I have a few questions hopeful someone more experienced can help.

1. What platforms normally do you use to find a remote developer?
   so far, I only know freelancer.com. So basically post your project requirements and then receive bids from developers and you chose to hire one. But if you can share your succesful experience would be appricated.

2. How do you sign the contract with them? as well as the NDA and how to ensure all IPs beloings to yourself?
   I hasn't created any contract myself before. Is there any site which can help to generate those contracts? will the contract signed protected by international law ( e.g. the remote dev might work in some other country)