That's great that you have a month - loads of time - although will you be doing your course Mon-Fri in Dublin? So just the w/e for other things?
Do you have somewhere organised to live? The website everyone uses here for renting, is
Daft - that covers short-term renting too
I'm not sure what famous stuff you've planned to see, but in Dublin I'd recommend Kilmainham Gaol & the Rock n Roll bus tour - both are quite unique and interesting. You should also sign up to my friend Jeorg's newsletter - Dublin Event Guide (for free events) - I put the link in my starter kit - he sends it every Friday, and he lists loads of stuff that's going on each week for free.
I live near the beach at Sandyford - that's a gorgeous walk if you like walking. The postcode system in Dublin works like this:
- even numbers = south side of the River Liffey
- odd numbers = north side of the Liffey
- the smaller the number = the closer to the city centre (it took me ages to figure that out when I moved here and was looking for somewhere to live!)
The Dart train is also good, and can take you right down the coast to Dun Laoughaire which is gorgeous, to the far north areas like Malahide and Houth - I haven't been to Houth yet, but do plan to go as it's supposed to be lovely! Let me know if you want any more!