E-mailing a contact prior to first round interview?

Is it a good idea to e-mail the person you networked with prior to your first round interview with their firm to say thanks/ask for advice about the interview?

I have an interview coming up on Tuesday and I was thinking about following up with my contact, saying thanks for all the help, i appreciate it, etc. And then asking them if they had any last minute advice for me aside from the obvious of knowing technicals/why banking/why X bank?

Or should I leave that last part out and just say thank you? Or should I not even bother since it's the weekend and they likely don't want to worry about e-mailing someone on the weekend.

thanks