Rononymous,
Congrats on your interview. I went through the process recently, and was offered a position. Use the search and review all posts in this site regarding Citation Shares, review CS homepage (history, management...etc), FAR 135 and 91K, JEPP PLATES!! (study the intro section, if you don't have it you can order it from Jepp), climb gradients (conversions, standard, non-standard), spend a little time reviewing ATP written questions, and always think customer service. Most of all relax (I know that's easier said then done) and know they wouldn't call you in if they weren't interested. I studied pretty hard over the material I mentioned and felt over prepared. Come in well prepared and show them you did your homework, and that CS is the place you want to be and you should be alright. GOOD LUCK!