Here are some job boards you can start with: remotejobsclub.com 100jobboards.com weworkremotely.com
If it's not stated in the ad whether they accept candidates outside of EU and US, you can contact their HR manager or team lead via email or LinkedIn and ask. I've hired people for several positions in the past, and I never mind answering questions people send me if they're not covered in the job ad :)
I've worked at 3 remote companies so far, and @ramiro pretty much covered everything that needs to be taken into account when managing a remote team - the most important practice from my experience is to have everyone use their computer for meetings - it's difficult when you're the only person that's not in the room.
Also, one important aspect of remote work is that you lose the opportunity for watercooler chats which can lead to some of the best ideas and better collaboration. One great solution for making up for this is using Donut - it schedules a virtual coffee/beer with one of your colleagues through Slack e.g. once in 2 weeks - that way you get to hang out and chat remotely with colleagues and get to know everyone on the team better!
Hope this helps :)