Confused by not knowing what to put into Schedule C and Principal Business Codes

You don't need a "business license" for Uncle Sam.

There is a business code for "Consultants", which I think covers your work; there might be something better, but don't sweat it. All you need at most is a well executed Schedule C. Find instructions and follow the detail. Make an honest effort to follow it. File what you produce. That's the spirit of the IRS rules, I believe. Schedule C is also a good place to tally your expenses (no self-employed work ever proceeds without expenses). Auto mileage, prorated depreciation on equipment (you computer and peripherals), health insurance. etc. are all candidates. It's really acknowledgment of free enterprise and entepreneurism, in my opinion. So go for it. If you have no ideas for 1005, then set up early-on a Schedule C worksheet for '06.

If you're looking at the TurboTax screen saying "Enter your business code," click where it says "See List" and choose from the codes in the pop- up list. The list shown includes the most common codes. To access a complete list, look at the bottom of the pop-up box and click on "Business Codes".

As you probably now realize, the IRS wants to know here what kind of work you did as a contractor. The code identifies the kind of work. It doesn't identify you or your client. Choose an appropriate code from the list TurboTax provides.