If you haven't read anything in the Munster dialect, some things might be confusing to you. Here are some basics that should prove helpful, as well as a few hints about the particular Irish of Peadar Ua Laoghaire.
Like always, when looking up a word, strip off the inflection (lenition, endings...), and look for the closest thing. Use my glossary for starters. There is a short glossary in the back of the book for truly unusual spellings and words. You will need at least the Ó Dónall dictionary, and Dineen wouldn't hurt either! Dineen has an addendum at the back that sometimes is useful, too.
this can be several things. It is the past particle that precedes a past tense verb. This is missing in the official standard, except as a d apostrophe before a vowel. But it is the reason for the lenition of a past tense verb. Do cheapas = cheap mé. D'imigh sé. Sometimes it is not used (in common speech), like 'Bhíos' instead of 'do bhíos.' It can also be the relative particle, in place of 'a.' An fear do chuaigh abhaile = An fear a chuaigh abhaile.
Munster Irish uses inflected verb endings. Here is a summary of the main ones you will need to know.
Some of the irregular verbs are not quite as irregular in this dialect! Likewise, the rule about not eclipsing between 'dentals' does not apply - eclipsis always happens. So this is easier than standard Irish!
Speaking of eclipsis, if we have a choice between eclipsing and leniting, we eclipse. In this particular Cork dialect, at least in this book, often adjectives are eclipsed if their nouns are. Not hard to read, just different.
I read this as 'Dá mba rud é.' It's kind of an extra, like 'should it happen' that should I finish this sentence...
'leis' is sometimes uses as 'freisin' or 'leis sin.' Kind of like 'too,' or 'along with that.'
This is the same as feicim. Curiously, this is not only more common in Munster Irish, but also in Ulster Irish.
Here's a link about this by Antony Green.