Medical billing work from home positions are great for some people, but they aren't ever as easy as the spam e-mails and scam websites tell you. You can't pay $25 or $50 for a training kit, and be magically qualified to do a job that usually requires extensive training from a company or a year or more of technical education. It's just not feasable.
These companies that tell you that you're able to do medical billing work from home with little or no effort are-- excuse my frankness-- full of crap. Medical billing requires special training and a lot of work. You need to understand medical insurance, codes, and charts at a minimum to do this job. You also need to have accounting and bookkeeping experience, along with other billing related skills. You can't just buy a training package and instantly become qualified for medical billing work from home.
Another myth about this job is that by working from home, you're entitled to more freedom and time with your family. Sure, you'll have more time because of the time saved from commuting, but you'll still need to put in your 6 to 8 hours a day, at least, to make a living. You'll need a home office that is capable of allowing you to do productive medical billing work from home, including internet access, fax capabilities, a dedicated phone line, and plenty of storage on your hard drive, either external or internal.
So next time you see an e-mail that says you can "make millions from home doing data entry and medical billing, with almost no effort".... pitch it, and move on. A real job will be more work, but will also be more fulfilling. Working from home is an awesome gig, but only if you find the right position that suits your specific needs and talents.