BTI will assist if you are a client of BTI and will help make the best decision for your needs. Contact your hosting provider and have a SSL key generated by the network administrator. Depending on provider and operating systems this should take no more than 24 hours. Once you have received the CSR, you will need visit either Verisign or Thawte's website to instigate the enrollment process. At some point in the enrollment process, you will be prompted to submit the new CSR through their enrollment form.
Online submissions are very straight forward and helpful.
Thawte has a 24 hour online help area which will answer any issues you may encounter. Ensure you have all your company information handy for verification. Depending on state or provincial incorporations, you may need to FAX info to the issuing company and this process takes approx 1 week. You should receive your server KEY notification for pick up by issuer or to-be emailed. Once you have your KEY notify your host company for integration to your site.