Pronunciation
Firstly, the "air" sound as in "spare," "chair," "pair" and "air" itself, etc, is pronounced as in "car." Parallel with this is another group of "air" sounds, such as in "pair," "chair," "there" and "where," which can also take the long "ee" sound of "eel", "reel," etc. I don't know why this is so, and it's a matter of taste which version is correct.
A similar situation arises with the "igh" sound in such words as "light," "right," and "night." Most of them take the double "ee" sound, for example ""leet," "reet" and "neet." But some take the long "ay" sound, as in "late," so we have "height" becoming "hayt," and "right" in some cases becoming "rayt." Again, it is a matter of feel.
In some words, the final "r" is rolled or emphasised. In one special case, the word "doff" is pronounced "dorf."
It is often said that Lancashire vowels are broad, meaning they are longer or sometimes more guttural than in Southern English.
Then, there is the pronunciation of "nought," "bought," "thought," and suchlike, as "nowt," "bowt" and "thowt."
Strangely, "caught" becomes "catched" and "taught" becomes "larnt" (learned). "Bowl" is pronounced like "cowl," while "old" and "cold" are similar. There are other differences, but these are the main ones.
Dialect
There are many dialect words, of which I have used but a few in my novels, for instance "fawce," "mournt" (mustn't).