Partner airlines' websites are a good place to start, although not all have loads of info. Wikipedia is an excellent source of info, detailing the basics behind relevant mergers, brief histories, fleets etc (although you should just bear in mind that it might not be completely up to date. As for info about CTC, their website is as good a place as any to get the info you will need. The interview is going to focus a lot more on you and your experiences and qualities. There is some info if you read through this therad about stage 3 too.