I am Guyanese citizen (South America) with a USA visitors' visa interested in visiting Turkey for tourism - a maximum of two weeks. How do I go about getting a visa?
According to Turkish Ministry of Foreign Affair's website, you can get a visa up to 15 days (if you have a special passport then you're exempted from visa up to 90 days). To quote:
Guyana: Official passport holders are exempted from visa for their travels up to 90 days within 180 days. Ordinary passport holders are required to have visa to enter Turkey and they can get their 15 day period visas from Turkish diplomatic representations abroad.
And by "official passport" they mean
The term "official passports" covers diplomatic, service, special and official passports.
According to Relations between Turkey and Guyana section of the website, The Turkish Embassy in Caracas (Venezuela) is accredited to Guyana.
When you go to Turkish Embassy in Venezuela website and click on Consular Services Menu, you should choose "TURKISH EMBASSY IN CARACAS" as your closest diplomatic mission and you will be redirected to Consular Procedures website where you can find more information about applying for E-Visa.
To apply for e-Visa you should go to e-Visa - Republic of Turkey Electronic Visa Application System.