I've set up several forums on my home server and I co-admin on a professional forum. The pro forums are running UBB Threads. Great software, but a little limiting. For my forums, I run phpBB. The software is easy to install, easy to upgrade and easy to mess around with. There are "mods" for practically any feature you'd want to add and with the easy integration, it's as simple as pointing the control panel to the installation file for the mod you want. Their forums are top notch and pretty much any questions you may have are there, already answered. If not, they are quick to help out. Best of all, phpBB is completely free.
One thing I'd recommend is a basic, working understanding of HTML, CSS and some PHP. If you can't program in these languages, at the very least, you'll need to be able to edit existing code if you want to change your look. However, it should be noted that there are thousands of "skins" out there, all of which can easily get you really close to the look you are going for and then minor changes (like switching out the logo) are easy.
Read through the forums, have a look at some of the forums people have built and, if you want to give it a try, download it and mess around for a bit. Because it's free, if you don't like it, there is no loss!