Apply directly to the embassies or consulates of the country you plan to visit. Passport agencies cannot help you obtain visas. You can obtain a copy of Foreign Visa Requirements from the Consumer Information Center, Dept. 438T, Pueblo, CO 81009. It lists the entry requirements for U.S. citizens traveling to most foreign countries and where to apply for visas and tourist cards. You will need to fill out an application form and give your passport to an official of each foreign embassy or consulate.
Some visas require a fee.
The process may take several weeks for each visa, so apply well in advance. If the country you plan to visit requires a tourist card, you can obtain one from that country's embassy or consulate, from an airline serving the country, or at the port of entry. For some tourist cards, a fee is required. Check entry requirements while you are planning your trip. Some countries require only proof of U.S. citizenship to enter and depart the country.