Tulip - as long as you go into this eyes-wide-open and realize that you may be lead in a different direction (like Jo-Anne), then this may be for you.
If you are the kind of person that takes initiative, can work independently, think quickly and you have an attention to detail, starting a billing company may well be a good fit.
There are doctors and other healthcare providers that do need billing assistance that aren't planning on becoming a part of any hospital - you just have to wade through the others to get to the right potential client.
You can find a lot of forms and such from Don Self's website at
www.donself.com
You will have to be flexible in your approach - not all doctors need a billing company, but a lot of them have old, unpaid claims, need a temporary biller, need help with credentialing, need understanding of where they stand financially, etc. As long as you figure out what an office needs and then meet their needs, success is achievable.
Also, please realize that you are just as responsible as the doctor is for the privacy and security of patient data and you must take steps to protect confidential information. Any doctor worth his salt will ask you to show the preventive steps you have taken.
And finally, having a compliance plan in place BEFORE you start marketing will prevent in-experience from showing... Most doctors will ask you for a copy of your compliance plan, so be prepared to present one.
Good luck to you.