From what I have heard here in Ohio you need to register your business name if you don't use your own name in it. For example my wife owns RadPythons Limited, previous to getting it Registered we would have had to use Shandra's Radpythons, Amon's Radpythons, or Shandra Amon's Radpythons, but the name Radpythons would still have been usable by others so it could be a non-related business and be called John's Radpythons. Also if someone else decided to register the name, RadPythons in our state before we did, we would no longer be able to use it. Also without getting it registered your not supposed to use LLC, LTD, or Limited.
As far as tax ID numbers go, you don't need one. We still claim the business under our personal SSN#. We have a company tax ID, but we don't use it yet. When we get big enough and start purchasing things under tax exempt status we will need to start using the tax ID number to protect our personal SSN since you have to give that number to anyone you purchase tax exempt goods from.
Next would be logos and such and then we get into trademarks and Copy rights and what each of these give you control or and the ability to go after some one for using them.
It would be interesting to get a legal-ease forum to help our hobby better understand the basics of business such as names, LLC's, Corporations, trade marks, and copy righted material. Just not sure how many times you can
on the same topics. Granted we have done it with many other topics over the years the forum has been here. lol