Second 'turning'??? No, I'm afraid not. It's turn.

That wording is fine Helen, or you can take the shorter version and go with what Todd said. I'd suggest putting a please somewhere at the beginning or the end of the sentence, but it depends on how you say it really. 'Take the second turning on the left' (In a normal tone of voice) OR 'Take the second turning on the left' (In an angry tone) If you were to say '' Please take the second turning on the left'' OR '' Take the second turning on left, please'' It comes across more polite.

You can simply say "Take the second left." Whomever you're talking to will understand to pass the first street and turn left at the second.