You might as well bite the bullet and spend some time rote memorizing the pronunciation rules. It seems to me that this is the first and most critical step in this process, and anything else is a waste of time until you have mastered that.
Fortunately, the rules of pronunciation in French and Louisiana French are quite similar, and are in general much simpler and more regular than English. Spanish is easier though.
I don't think there is really any alternative at this point. If you are focussing mainly on Cajun and Zydeco songs, it would not be particularly helpful to rely on any Standard French dictionaries as that will throw you off just enough to be annoying.
Standard French and Cajun doesnt seem to similar to me. I have the Rev Daigle Self Taught book, he does have some good pronounciation guides in it.
On top of it all, the pronounciations change a little area to area, though Cajun French does share some common rules, for example in "tre" or "dre" endings, the "re" is not pronounced unless followed by a vowel or silent consonant. And Cajun French seems to eliminate as many vowels as possible in pronounciating, such as "je te.." becomes "j't'..".