Steps to setting up a business for selling apps on the Android Market

I've been struggling with trying to understand all the different options to pay sales tax on apps sold on the Android Market. I've read a whole bunch of stuff but I'm still confused and a little worried that I'm missing something important. I'm hoping someone can tell me if I got this right. I'm in PA and have a salaried job. I don't intend to have any employees or sign any contracts. These are apps I write in my spare time and unless lightning strikes won't make more than a few thousand a year (if that).

The easiest way seems to be a sole proprietorship - Register, possibly register for a fictitious name, sign up to pay sales tax and pay it quarterly. Finally file a schedule C along with my regular 1040. I'm guessing I don't have to make quarterly payments for income taxes because my current job does that anyway and I usually get a refund for that at the end of the year. This is assuming I don't sell a lot of apps. If I do, I can see filing a little extra quarterly.

Does this make sense? LLCs and S-Corps seems too complicated for my 1-person app development side business. And will probably require an accountant which seems silly if I don't make more than a thousand odd bucks. If I start doing more stuff, I can always change from a sole proprietorship to an LLC or S-Corp.