If going by taxi go on Saturday. Less traffic. Nazereth will be packed on both days. Price should be about 200 shekels. There is a bus that runs on Saturday too, no. 332 operated by G.B. Tours. Check www.otobusim.com , there is a button for English too.
Assuming you are coming on a ship you will find taxis readily available at the port. The cost is around 200 shekels if memory serves me correct. The fares are prominately posted on the wall as you exit the terminal building. Note that taxis are more expensive on Saturdays, but there is much less traffic in Haifa so you'll get to your destination quicker.
There are also sheruts but they don't go to the sites you would want to visit.
-:- Message from TripAdvisor staff -:-
This topic has been closed to new posts due to inactivity. We hope you'll join the conversation by posting to an open topic or starting a new one.
To review the TripAdvisor Forums Posting Guidelines, please follow this link: http://www.tripadvisor.com/pages/forums_posting_guidelines.html
We remove posts that do not follow our posting guidelines, and we reserve the right to remove any post for any reason.