I am going to apply for a position inside my department. How far back should I include work experiences? do I need to go all the way up to first job? Would last ten years be enough?
And the further back you go the less detail you need to mention in regards to the job. Focus on your recent accomplishments.
I was always told that if some of your previous jobs have nothing to do with what you're trying to get now, just omit it. Unless of course you worked in some fancy big company and want to show off a little.
Yes, last 10 years- although, if your experience with the company goes beyond 10, it wouldn't be a problem going back beyond that. What you can do to save space is just say something like: ** Previous positions with XYZ COMPANY included POSITION TITLE, POSITION TITLE, and POSITION TITLE.
The resume is a marketing tool. If it helps you get the job, put it on the resume. If it doesn't help, omit it.