Anyone recommend some accurate reading on the Irish troubles in the early 20th century?

A Secret History of the IRA  by Ed Maloney. I think I got it at Barnes & Noble. I've read a few books on the subject and this is my favorite. It's so detailed in fact that it can be a little dry to read.

I read this one from the British perspective.  A Long Long War by Ken Wharton.  It goes year by year during Operation Banner, the longest deployment of British troops in NI.  A damn good book.  Some parts are quite sad and the room got quite dusty when I read it.

Or "The IRA A History" BY Tim Pat Coogan

Excellent read, but hot damn, is it dry.

If by early 20th you mean the Rising in 1916, and the Civil War soon after. I can get some titles for you out of my library.
The Troubles refer more to the late 60's  and into the early 80's I can find some good titles on that as well.

To get you going find a book titled "Paddy's Lament" that will give you a reference point.

Agony at Easter is a really good read about the Dublin uprising and situation at the GPO. It's written in a way that reads like a fiction novel but with actual researched oral histories. I'll have to go through some more of my stuff later if I get a chance. I did my thesis on the IRA and the background of Ireland and the early Irish groups were a big part of the modern IRA.
Agony at Easter

This one is good as well Armed Struggle:The history of the IRA


This is a really good movie that deals with the early Irish troubles: The Wind that Shakes the Barley

Good luck.....it is a very convoluted and complicated area of study.