Artesana Zayda is on the way back from Tikal if you are staying in Flores or Santa Elena. (It is about 30 km. from Santa Elena.)
What to buy: They carry very nice carvings, pottery, and clothing. They also have a good selection of books on history and culture in English, including the Popol Vuh.
What to pay: This shop is not inexpensive, but you might find things you won't see elsewhere.
In the Museum building, near the patio cafe, there is a good bookstore with a predictably large selection of books for Tikal and the Mayan world in general. The images here show the titles that I purchased. After stumbling around Tikal with only a map, it's nice to have the perspective that such reading can provide. The bookstore also has a variety of souvenirs for all ages. The images show books that I bought. I particularly like the John Montgomery book on Tikal, but Rigoberta Menchu's Mayan Biography is also a classic for anyone's library.
LOCATED NEAR THE CAR PARK AND RIGHT BY A POND IS A HOUSE (CENTRO DE VISITANTES) WHICH GOT A RESTAURANT IN IT AND A COUPLE OF SHOPS TO BUY YOUR SOUVENIERS.
What to buy: WOODEN HAND CRAFTS, BOOKS, POSTCARDS, ORNAMENTS, AND OTHER STUFF.
The main park building has a small restaurant for breakfast and lunch, some interpretive displays on the park (free but not very in depth), and a large area where native crafts are on display for sale.
What to buy: There are many woven craft goods such as place mats, table cloths, and clothing. These are produced locally. There are also souvenier type items such as key chains.
What to pay: You can bargain - it is expected.