How Do You Pronounce These Words.

[Barsel]

I'm from the North, my husband is from the South.
The first time he heard me say certain words like book and look, he told me I should pronounce them as buck and luck, but i know a lot of people here in the North that pronounce the oo's as that and not as a u.
Is it a North/South thing?
How do you say the words that are spelt with a double o?