1) Choose and establish a business entity *before* doing anything else--you want to be able to enter into leases, contracts, etc. in the name of the entity, not yourself, so as to avoid personal liability for business obligations. Either an LLC or a subchapter-S corporation is a good choice for a small business, with the LLC being slightly less formal and more flexible (and involving less paperwork).2) Trademark is based upon usage in commerce, so you can include the "TM" next to your name and logo as soon as you start using them, and also start the registration process (to get the "R") mark) once you start operations. Rememer to pick a name and logo not in use by anyone else (and not too similar to a name or logo used by another), so that you can trademark it.