Tikal

Maps
are available outside the Visitor's Center for Q20 $2.80 US or if you have a digital camera just take a photo of the sign with the map on it shortly after you pass the ticket box.
Walking trails
wind through the temple complexes.

There are buses to Uaxactun that leave around 3 and 6pm times approximate. The price is Q15 for the bus and Q25 for park entry. The buses return at 5 and 6am the following day, and can be well worth it if you are planning to camp at Tikal anyway. Take food, water and sleeping gear with you a hammock or sleeping mat and mosquito net should be adequate.