The interview process is fairly standard from my experience. It starts with a phone screen from HR, and if that goes well, you'll get set up with a hiring manager phone screen or onsite interview. Typically, if it's an onsite interview you'll meet with about three or four other managers in your department. If you make it through those interviews, the hiring manager will typically set up one final interview with his direct manager. After that, the offer will come pretty quickly. Sometimes there is difficulty with scheduling, and internal deadlines, so the process can drag on, but in general, an expectation of about three weeks is fair.