As a Griffon Pilot, I'll give you a sample from the last 12 months
Exercises - 5 weeks
Taskings away from home - 10 weeks
Professional development - 5 weeks
Aviation related courses - 4 weeks
Misc days here and there total to another week or so.
Total that up - about 25 weeks a year (6 months total).
That doesn't include any major deployment (like Bosnia). Early on you'll have alot of BS PD courses, then later on, more flying related courses. I have a pretty hectic schedule, but as a typical pilot, I would expect a minimum of 3 months total away from home. But like you said, varies on an individual basis.