When a planet is in good dignity, it makes it easier for the person with the placement to learn the lessons the planet is trying to teach. This in turn makes the experience more positive, because you don't have to constantly repeat the same lessons (if you don't learn the lesson first try, the difficulty will increase so you will learn the lesson). Although with retrograde planets, usually the lessons come in 3's - so it should take each lesson at least 3 attempts to get it right. Retrograde planets show where we in a sense failed in our past-lives, which is why you will get it right in the current incarnation.
Yogakaraka planets are your friend, which mean they work with the house they are in and aspecting to help you. So for instance, Saturn in the 8th in poor dignity will make one critical of the in-laws and may create distance and separations. In good dignity, Saturn respects the in-laws, and acts in a mature and dignified way towards them.
In relation to your career, wealth and children; expect all of Saturn's usual characteristics of delays, restrictions etc - but he is your friend, so his influence on those houses will be positive for you.