What is a Saturn return?

I mean i vaguely know what it means but i don't know enough. How do i interpret it in my charts and how can it help me understand things more?

Saturn return happens when Saturn returns to the position it was in during the time of your birth. It takes about 30 years before Saturn returns to it's same position.

A Saturn return is important because it will be aspecting your natal planets, again, exactly the way it did when you were born.

Helpful Information: http://www.huffingtonpost.com/shannon-kaiser/saturn-returns_b_4275974.html

the first Saturn return happens around 28 years of age when it comes back to hit your Natal saturn by conjunction. Depending on what house it is in, will be the area of the experience. Plus whatever aspects are coming from elsewhere in the chart. It is a time for taking more responsibility, sometimes people have children at that time. It is a maturing aspect where you need to get real and work hard for what you want. It is a karmic influence where you reap what you sow. I would look at books and articles online for further information.
You have a skewed chart with the house system used as you are in Ireland but if you were to try the equal house method it may be more valid as the houses will be more evenly balanced.