Locating vendors/business side of things

[Ewest53]

I was wondering, those of you who do computer repair/upgrades on a daily/weekly basis or whatever do you bother with a sales tax license and locating vendors so you can buy wholesale and make a small profit on the sale of the hardware to be replaced as well or do you just go to the local computer store and pick up parts as need charging what it cost you to buy it? I am wondering because I plan on starting my own part time business to do on the side of my other job. I have been upgrading and repairing computers for quite a few years but the business side of it isn't my strong point(that's what the girlfriend will be for). I was planning on registering with the state as a sole proprietor for the time being and possibly converting to a LLC in the near future. The reason I plan on actually registering with the state is because I plan on doing a lot of business and hopefully turning this into my full time job in the near future(depending on how things go) In my situation it wouldn't take that many jobs a week to surpass what I make at my current job....10 at $35 an hour to be exact...I am lucky to bring home $330 a week currently but I only have one semester left before I will have my CS degree. Would like some input from those who actually do this as a full time job.

Well I see my girlfriend is trying to get some ideas for Christmas presents for me(the What every tech should have post, she really should have registered her own name )

Thanks for your time
Eric