I made a mistake setting up a username for my Facebook account and I wanted to share it so maybe others won't make the same mistake.
First off lets get some terms out of the way so you'll be able to understand what your reading here and in Facebook forums. A Facebook Profile is for a person and a Facebook Page, (Formally a Fan Page), is for a business. A Username, (sometimes called a vanity URL), is a way to make you or your business easier to find. For example my business, Your Art Director, has the Facebook link, http://www.facebook.com/pages/Your-Art-Director/122752040711, if I had not made a little error I could of set up a username and made the link, http://www.facebook.com/YourArtDirector, (Don't click that link, it goes nowhere). Much easier for people to find.
You can go to this link to sign up for your Facebook Page for your company, but you need to understand that Facebook was intended to be a place for individuals to connect and you will need to link the company page to a personal profile to be able to do certain things, like get a username, but I'll get to that later. Here is a little known rule, you're only allowed one Facebook account, and according to Facebook rules you can lose access to all your accounts for having more than one. So once you set up the business page you are expected to set up a profile, or link it to your existing profile. Then your going to want to set up your user name to make it easy for people to find you, but you can't yet, you must have 25 people like your business page before you can set up a user name. So copy the long link and email to everyone you know and ask them to log into their Facebook accounts and click the LIKE button at the top of the page next to your business name.
This post from All Facebook, How To Create A Business Account On Facebook Without A Personal One, says you don't have to link the business page to a personal profile, and that's true, however I was unable to make a username until I had linked the page to a profile. I suggest you set up your page, get your 25 LIKEs and then try to make a username at this link. Maybe it will work for you.
My mistake was that I entered the username I wanted for my business page in the personal profile settings. To set up a username for a business page you must be sure you do it here, facebook.com/username. You're only allowed to change your personal profile username once. As soon as I realized my mistake I quickly changed the username on my personal profile, for the one time, in hopes the username would become available for my business page, but alas, it didn't. I have seen many posts, i.e. Transfer personal facebook username to business page, about people that have made the same mistake asking Facebook for help. Here is a post on changing usernames, note the red letters warning you you may lose the username altogether.
I am now talking to Facebook Tech Support. They are asking for proof the company names are a registered trademark. Hopefully I will be able to get it all squared away. Good Luck to you, I hope this post helps.