hi, currently a 911 dispatcher here. Check with the department you want to apply for if you can do a 'sit along' for a few hours. It'll help you decide if that's the place you want to work in or not.
A couple of things: Typing is key, some departments require 40 words per minute, but it helps if you're a lot faster than that. Closer to 60 words per minute is key.
-Another few things is how you react under stress, and your prior experience with emergency services. If you've been an emt, leo, or firefighter it will help a bit.
It's not necessarily hard work, but it can be stressful and the shifts can really get to you. Keep in mind as a new dispatcher you might get the overnight shift. Coworkers can also be a blessing or a curse, depending on their attitudes towards the job. It's a lot of females usually working close together. I'm a woman, and I find them annoying most of the time.
I like the job for now, but I know for me it's probably not a job I'll be working in a few years. However that's because I am going to school to become a leo. But it gets you some interesting experience and you get to talk to a lot of weird people. feel free to im me if you want any more info.