I have decided to only include institutes for two reasons. First, they are more likely to hire working travelers for six months or so. Second, they are less strict about visas. Working without a visa is illegal in Peru, but these places will hire you as a "volunteer" and give you a "stipend". Usually if institutes give you a stipend, you will get about 500USD a month. Some places will include room and board and if they do, you will probably get a lower stipend.

If you're interested in staying longer than six months, you should try applying at schools or universities, not only will they give you a longer contract with more benefits, but will probably go through the paperwork to get you the coveted work visa. Whether you want to stay short or long-term, I suggest you look at The Ultimate Peru List which has heaps of info from finding work, to get visas, to being a tourist.

English Institutes

There are no lack of English institutes to teach at here in Peru, however, there are a few that stand out in being the crème de la crème in regards to pay, work environment, hours, and treatment. These institutes continually receive positive feedback from teachers who have worked there. Some teachers go thinking that they will stay for a few months and end up staying years. Others stay for a bit, leave, then return again. One thing that stands out is that the majority of these institutes are run by expats, so they have first-hand knowledge about what it's like to live in a foreign country.

Arequipa

El Cultural: The language institute to work at in Arequipa.

Maximo Nivel: See Cusco

Chachapoyas

International Language Center: http://perso.wanadoo.fr/internationalcenter/
Located in the jungle away from the noisy city, Fidel has volunteers teach English, German, French, among others in exchange for room, board and a small stipend. Many teachers have taught there for a couple of months only to go back miss the atmosphere and go back and teach again.

Cusco

Maximo Nivel: The main branch of MN is here in Cusco and they allow teachers to teach for a few months in one city, then go to another. Ken acknowledges dedication and promotes those teachers who stay with him for a long time.

Excel: Known for its laid-back work environment which allows teachers time to explore Cusco and the nearby area.

Lima

English for Life: Started by a British expat a couple of years ago and was recently passed on to another Brit as the original owner moved back to England. Known for its small groups and personalized attention, the owner may occasionally need people to teach part-time.

Master Business English: One of the two top Business English Institutes in Lima. Teachers receive about 6-10 USD an hour and only work part-time.

Business Links: Known as the best kept secrets among expats, this is one of the top and oldest Business English Institutes in Lima. Pay is 6-10 USD an hour.

Multilingua: The Spanish langauge institute that he runs is older than the English one, but he still needs teachers from time to time to help out with expanding classes. Expect part-time work.

Talara
L and B Language School: lyb.teachers@gmail.com, The only expat run institute in Talara not only has classes in the institute, but also sends teachers to nearby schools. If you're looking for a year-long summer, Talara's the place for you.

Trujillo
El Cultural: Similar to El Cultural in Arequipa, the one in Trujillo is the English institute to study at. You'll find expats who have been working here for years.

Final Tip

No matter what city or institute you decide to teach at, be sure to talk to or email former teachers as they can give you an inside look on what it's like to teach there.

The LA Job List http://www.thelajoblist.blogspot.com Find a job teaching English in the Caribbean, Central or South America. Over 700 schools in 19 countries. The Ultimate Peru List http://www.theultimateperulist.blogspot.com everything you need to know about Peru from work, immigration, getting ready, settling down, free time, legal matters, tourism and more.

TEFL Tips http://www.tefltips.blogspot.com Useful tips for those teaching English.