Remote work requires mostly commitment from all involved parties. Though the burden is usually higher for the remote worker than the on-site people, on-site people have to be very aware of the fact that any communication that happens on the corridor or in the staircase will be communication that won't reach the remote worker.
Technology is only going to "fix" it for you to a small extent. Take video-conference with everyone in one room plus a remote worker. There are very real latency issues. If everyone talks it will be hard for the remote person to get attention. Also, not everything will always be clearly audible. And last but not least you can't just take out a sheet of paper and pencil and draw up some sketch. Recording your meetings (in a portable format) can at least offer an alternative way to communicate the parts that got lost during the live meeting. It's also a nice reference (even without remote workers) for everyone.
Maybe I'm a bit too pessimistic about these things (having had to work with several remote devs under me, though), but the commitment and communication in my opinion is very very important. Way more important than any technology could be.
Keeping motivation up is, too. Communication is a way to do it. Clear communication is an extra effort, though. Especially when you don't have facial expressions from the discussion partner available (e.g. in a phone conference).
Anyway, if you want to take the - very real - risk start early with communication via an instant messenger and email: even on-site. Both for 1:1 and multi-user. It will (hopefully) raise awareness in how many ways communication is cut down with someone working remotely. All those side-channels are gone. Both with email and instant messenger you will notice latency issues, too. More with email than with instant messenger, of course. If the worker next to you does not reply immediately you may know he's in the bathroom or very concentrated and working. How about the remote worker. Is he working? Is he perhaps slacking off? You have to be able to fully trust your remote worker. And that trust relationship has to exist before the person goes abroad ...
I've experienced functioning remote working relationships, with very disciplined and committed people. But in the majority of cases I experienced, it was a waste of time and sooner or later led to one of the involved parties giving up on the other (with changing roles and varying consequences).
Another good idea might be to try and work from home for some time yourself. Even a week will be enough. It will show you the temptations and will make you aware of the discipline it requires to work remotely (even if not that far away ;)). It will also give you a feeling of whether or not you think this person would be suitable for remote work (assuming you feel confident in judging the person in question already).
Edit: one more thing. With one remote worker we had rented an office place for him at his remote location. This way some of the temptations that exist when working from the home office were removed. And it worked better than with those that worked from home.
Edit 2: one more thing I have noticed is that some of the on-site people who are not as comfortable with written communication but don't belong to the immediate team (system admins or other coworkers) may cause disruptions. If they do not reply to the remote worker (e.g. problems with VPN or other services) it will foster the feeling of the remote worker of being "left alone", despite all efforts within the immediate team. In such cases it may be best if there is an on-site liaison for the remote worker within the team that will take care of such requests by actually walking to the person that would otherwise not reply by email or instant messenger.
And one more note about trust. It may sound somewhat hostile, but it's what you will know from other occasions in real life as well: trust is built up very slowly, but it's lost within moments. That's why I consider the commitment the prime prerequisite. Commitment will ensure that the trust relationship will survive.