I had a reseller license in California for several years. I went to the local office of the state tax collecting agency and filled out some forms. For the most part, they just want to know that you're a legitimate business and not someone who's looking for a resale license just so you can buy wholesale and avoid paying sales tax (at least initially). Periodically you're required to report your sales and inventory to the state. In California the time period depends on how much business you're doing. (I only had to report yearly.) In my experience, the state will readily give a resale license to anyone they think has a real business. If you don't file the sales forms or don't have real sales, they will pull the license.