The experience I had was relatively quick by company standards -- normally the process takes a month or two, where in my case it was a matter of weeks. I had 5 interviews prior to receiving an offer. In the order in which they occurred:
1) Phone interview with Director of European research
2) Phone interview with Research Director of my prospective team
3) 3 separate Face to face interviews (2 senior analysts, and 1 RA)
Everyone was friendly and imparted a strong positive company culture. The questions were varied, but focused mostly around IT markets (at the time the team I was applying for looked mainly at IT services and outsourcing). At this level they're not looking for someone who has expert knowledge in the subject area and basic knowledge should suffice. The key things they do look for are communication skills, writing ability, project management, and attention to detail.
My advice (especially once at the face-to-face interview phase), is to try to answer any questions about the IT market, but if you can't try to bring things back to topics you know about and are comfortable speaking about. A lot of the people in the company come from varied backgrounds and didn't join from IT backgrounds themselves so the key goal should be to prove your communication and writing skills.