Cardiff Lane is in Dublin city centre.
http://maps.google.co.uk/maps?hl=en&sour…
Zoom out twice (click the minus button twice) and you'll get an overview of the general area.
Oxfambridal in George's Street, may have other special occasion clothing too.
Oxfamhome
Oxfambooks
Dublin Fair Trade
http://maps.google.com/maps/ms?ie=UTF8&h…
Click on the name of the store, and look for "get directions", type in Cardiff Lane, and details pop up. If you think some of them go by a roundabout route, that is because they are driving instructions to cope with one-way streets. As you will be walking, you can take the more direct roads or plan a shorter route.
St. Vincent de Paul, across the Liffey and pretty close to you.
http://www.qype.ie/place/475753-St-Vince…
On the map, use the hand to push the red button straight up into the top left hand corner. Now on the bottom of the map you can see Custom House Quay Your hotel is across the river from there.
Gorta is pretty close too, cross the river and walk along the banks until you get to Capel Street. It is a fair walk, but within reach. It is at the third bridge after O'Connell Bridge, then turn right.
http://www.qype.ie/place/501510-Gorta-Du…
C.A.S.A. Charity Shop is also on Capel Street
WA WA Women's Aid is a bit further, but pretty close to Oxfambridal.
On second thoughts, it might be a bit far to walk, but if you were going to be at Oxfambridal, it might be worth the extra half mile or so.
http://www.qype.ie/place/498119-WA-WA-Wo…
After all that, I found another website showing many charity shops.
http://www.yelp.ie/search?find_desc=char…
On the map, look for those closest to the thin blue line of river at red marker no. 5. Take note of how close the yellow circular road (like a big yellow roundabout) is to your hotel, then by clicking on the map or the name of the store, you can gauge the walking distance and easiness to find.
http://www.icsa.ie/icsa/Main/mapDublin.h…
Click on Dublin 1 and Dublin 2
For Dublin 1, all except the Mater Hospital Shop are within easy reach.
For Dublin 2, all a bit further to walk, but within reach if you have good walking shoes.
Click on the name of the store for info about what it contains.