When beginning just the basics, do you have to register with the internal revenue peeps perhaps to say that you are still working, but self employed? Or can you deal with it all come tax bill time?

Lots of information at the following three links. You should register immediately (within the quarter when you start):

Quote: Estimated taxes apply even if you also have a full-time or part-time job and your employer withholds taxes from your wages. Estimated tax is the method used to pay tax on income that is not subject to withholding. If you don’t make quarterly payments you can be penalized for underpayment at the end of the tax year.

Estimated Taxes

Self-Employed Individuals Tax Center

Small Business and Self-Employed Tax Center

Thank you for the links. I still have not done anything for profit, only being an aid to friends and family in their personal imports. Though I hope to actually turn it into a business I haven't yet, and hence still have a lot to learn!

If you are not making any profit but have deductable expenses during your business evaluation period, then it's worth registering.