How to get to DUB and stay there!?!? (Dublin)

Hey Expats,

Zan here! I'm 25 from South Africa! I want nothing more than to find a decent job in Dublin! It would make my life! I have two Business Degrees in Marketing and Communication Management, and an International Teaching Qualification. I have lived in Europe before, and fell madly in love with it. How should I go about getting to Ireland and staying there?

Is it possible to fly to Ireland with only a one way ticket if you have 90 days in the country, or do you need a return ticket?
Is it a good idea to look for a job whilst in the country, or should I secure a job before going?

If anyone could give me some guidance, that would be very appreciated!

Hope to see you soon!