Well organised, friendly and offering an impressive wealth of knowledge, Sandemans' free tours take place three times a day and are an ideal introduction to Jerusalem's Old City. Bookings are generally only necessary in high season. Tips are appreciated (50NIS per person is appropriate). Most tours begin at Jaffa Gate; look for the guides in red t-shirts.
Sandemans also offers in-depth tours of the Mount of Olives (2pm, €30 including one-way transfer), a four-hour 'Holy City Tour' hitting the Old City's major religious sites (11am, €30), a three-hour City of David tour (2pm, €34) and a 'Shabbat experience' (5pm, €25) around the Jewish Quarter, rich in insights into Jewish spirituality,
Be wary of unaffiliated touts by Jaffa Gate also offering free tours and claiming they can give you free entry to various monuments (none of the monuments they visit charge for entry).