Hey, I'm from Dublin!
What dates will you be here? There could be some good gigs on around town.
Some places can be great of a certain weekend, and not so good the next, so it would be good to find when you're here!
The Garage bar, in Temple Bar, is small and dingy with great DJs from Wednesday to Saturday nights (Friday & Saturday being the best in my opinion - mostly 50s/60s garage, psych, punk, mod, etc...)
If you're looking for a good pint of Guinness, try the Stag's Head at Dame Lane or The Lord Edward on Lord Edward Street (beside Christchurch).
As for record stores, try The Rage on Fade Street (https://www.facebook.com/TheRageDublin)
Spin Dizzy Records in George's Street Arcade and there's another one in there too (can't think of the name)
Secret Book & Record Store on Wicklow Street (Tower Records is also on Wicklow Street)
There's a few around Temple Bar too, if you have a walk around there they should be easy enough to find (Temple Bar is small!)
Hope this is of some help,
Let me know your dates!
Michelle :)