On the right path to start up?

Hey guys! I found this site while searching for registrations and such needed for business startup. While my husband and I are not new to *self employment*, it has always been small odd jobs or contract work. My husband works full time as an employee, but has recently become certified in another area of work. He wants to start his own service business on the side. For one, it seems less risk since we will still have steady income from his day job plus insurance benefits. Two, it makes less work on the taxes. Obviously this will not be a full scale company and while he may, in the future, expand it with employees right now we have no plans to hire extra help. I have several questions to make sure we are understanding and following the logical course here.

We are choosing the sole prop because it seems easiest, and eventhough we'll both be getting it off he ground, he will be the only one offering services. Since we are married, I figure by law I own part of the business anyhow. I believe, also, that if we are a husband and wife partnership and the only employees, then for tax purposes we still file jointly and just add in the business profits under the self employment.

I have sent an inquiry to the county clerk regarding our business registration. It is my understanding that we will need to file a Doing Business As form since we are opting to use a different name than our own.

From what I've read, Texas does not require us to file with the secretary of state unless we change our company status. Is this correct?

I have not found any other requirements we need to do, unless we want to file for trademark/service marks? We may do this at some point, though the pricing I saw was around $3-400.  However, I found and downloaded the application for trademark with the secretary of state in which the fee is only $50. I'm not sure of the difference. I assume this would provide adequate protection for us, epsecially since we only plan to operate in our current county, and perhaps neighboring counties as well, but definately not statewide.

Now, as for filing purposes, on income tax we will be filing married, jointly and adding in the self employment form. This set up ok?  We will not need deductions like home based business as he plans to work out of a borrowed office. On the self employemnt can we deduct our normal fees like business expenses (matrials) and the like? Or is that specifically for corps and formed partnerships?

I hope I have not confused you. I'm still trying to sort it all out. Opening a self based business seems exceedingly easy, until you start getting bogged in paperwork!

Any help, ideas, suggestions, etc is greatly appreciated. Thanks in advance. have a beautiful day!

~Hilary~