Before I answer your specific question ponder this one. How long do you plan on running your message board? For a few years or until the internet dies? Will you make sure it gets transfered into good hand if you decide to no longer be involved? I don't think there is any point in starting a public forum without being committed to keep it going. When we started our site I don't think we could think as far ahead as now, but it's an interesting question to ask of yourself where you would like to see it go.
To answer your question, if you are fairly competent on a computer you probably could get by without programming experience. I would suggest learning how to setup a local environment on your computer using XAMPP or MAMP and doing MySQL backups and recovery, learning how to use tar, before taking your board online. Use this local environment to reassure yourself of what you are doing before you do it on your public board. I think learning command line is really crucial and there are some good screencasts over at Peepcode for a small fee to learn how to do this which are absolutely first rate.
Now, back to my aforementioned idea. If you really want to run your board for a long time I'd learn PHP. It's fun to learn and there are great resources out there. I do better with screencasts then books, and Nettuts has some great PHP articles and screencasts.http://net.tutsplus.com/category/tutorials/php/
I always suggest coming up with a few micro and macro projects to work on while you are reading a book that are outside of the examples they use for you to apply your new knowledge. You need to spend a few hours a week to stay on top of your new skills. You don't have to be pro. I can deconstruct code and make some modifications, for anything bigger I rely on an accomplished developer like Sirdude.
Sorry for the longish answer but I think these are important things to consider if you want to be successful at having a forum.