Hiya
Make sure you have lots of addresses that you need to look up clearly written out for the archives, as that is the main place for searching the 2 census.
Also if you are there early, there are a limited number of the microfilm machines attached to printers, so if you get one, it is very handy to print out any records that you may find.
The library in Pearse street also has most up the bmd index records on micro film, up to 1950 or 55, where you can search the index then go round the corner to the gro to get them printed.
Hope this helps