The benefits are IMMEASURABLE!
I've recovered two Akitas due to microchipping alone.
There are a few companies out there like: AVID and Home Again that you can choose from.
And it's just what it sounds like. There is a little microchip (about the size of a small grain of rice) that is implanted commonly in between the shoulder blades. And when scanned, this little chip emits a "prison number"-for lack of a better word
- that you call in to the company that created the chip. That company will then tell the person that scanned it all of the neccessary information to get the dog back home safely and notify them of any medical conditions they have on file.
The registry fee is cheap and it's a one time deal. No monthly bs fees and what not. You just have to be sure to submit your current info. if your vet doesn't do it for you. And every time you move or your dog develops a medical condition you should call the chip company and update their records.
Hope this helps.