Arrive early any day and you could cover most major valley destinations in about a week that way: two days east (Teotitlán , Tlacolula , Mitla ), two days south (crafts villages , Ocotlán market ), two days southwest and west (Zaachila market  and archaeological site , Cuilapan , Arrazola , Monte Albán , and Atzompa ), and one day northwest (Etla  market and San José El Mogote ).
More leisurely options would be to rent a car or take a tourist bus, or both. Get your car rental through either a travel agent or U.S. and Canadian toll-free car rental number before you leave home, or in Oaxaca locally: Hertz (tel. 951/516-2434, fax 951/516-0009, hertz_oax [at] hotmail [dot] com), Alamo (tel. 951/514-8534, fax 951/514-8686, oaxalamo [at] hotmail [dot] com), and Europcar (tel./fax 951/143-8340, tel. 951/516-9305, toll-free Mex. tel. 800/201-3333, www.europcar.com.mx ).
For tourist buses, a good bet is to go with Viajes Turísticos Mitla, which offers economical tourist bus transportation to a number of Valley of Oaxaca  sites, with multiple daily departures to Monte Albán . For more information and reservations, contact the bus departure ticket desk at the Hotel Rivera del Ángel (F. J. Mina 518, tel. 951/516-6175). For private tour options, contact their main office (tel. 951/514-3152), also at the Hotel Rivera del Ángel.
Alternatively, other agencies offer similar arrangements. For example, try Agencia de Viajes Caracol (tel. 951/514-1574), at the Hotel Trebol (corner of Flores Magon and Miguel Cabrera, a block south of the zócalo’s southwest corner). Their regular departures include Monte Albán, El Tule–Mitla, and Cuilapan–Zaachila–Arrazola. Many hotels also have economical tourist bus arrangements. See your desk clerk or lobby travel agency.