Lucrecia - "loo-cree-shee-uh"
Yuffie - "yuh-fee" Although "u" is normally pronounced "oo" in Japanese, it can take the form of "uh" when preceeding certain sounds. I think this case would be "yuh-fee."
Mako - "mah-ko" This is how it is pronounced in Japanese.
Shera - This should probably be Sheila, not Shera. "r" and "l" are very ambiguous in Japanese, being that they come from the same sound. Because of this, "r" and "l" are often mixed up when translating words into English.
Tifa - "tee-fuh" This is how it is pronounced in Japanese.