I'm taking over the day to day maintenance of a sitecore 6.2 installation for a corporate website. The vendor that originally designed and constructed it are no longer available to contact for information. Also, no documentation has been written on how it was designed or constructed.

My asp.net skills are good and I do have some understanding and exposure to Sitecore and will be attending training soon but in the meantime can anyone give me some ideas as to where a vendor would put the stylesheets that control the design and layout of a Sitecore website.