Be short and succinct and add a personal touch that shows that you have personality (that may be of interest to the listener if you have done your research on them). Just imagine what you would like to hear from someone else telling them about their career. No unnecessary technical detail (especially if they are not working in your chosen field) but just sufficiently to raise interest in what you are doing.
Always ask who will be interviewing you and research their career so you know what points you might have in common. I find LinkedIn a very helpful resource and would always check people's profiles before entering an interview.
Hope this helps.