How could I get the most benefit out of the Pimsleur programs?
In using the Pimsleur programs how do I check my progress?
What are the guidelines for success when using the Pimsleur programs?
What about regional language differences?

 How could I get the most benefit out of the Pimsleur programs?
To get the full benefit of each lesson, try to create the best learning conditions. Choose a quiet place where you can practice without interruption and a time of day when your mind is most alert and your body least fatigued. You might study in your car, listening to the program while you commute or travel.
Each lesson is approximately 30 minutes long. Dr. Pimsleur's research shows this to be the optimum period for learning, after which the mind loses its ability to retain new information. Try your best to work through one lesson each and every day. Whether you move on to the next lesson daily or repeat those you feel unsure about, it is important that you familiarize yourself with the language on a daily basis.
Once you've started the program, simply follow the tutor's instructions. The most important instruction is to respond aloud when the tutor tells you to do so. There will be a pause after this instruction, giving you time to reply. It is essential to your progress that you speak out in a normal conversational voice when asked to respond. Your active participation in thinking and speaking is required for your success in mastering this course.
Do not have a paper and pen nearby during the lessons, and do not refer to dictionaries or other books. The Pimsleur Method works with the language-learning portion of your mind, requiring language to be processed in its spoken form. You will only interrupt the learning process if you try to write the words you hear.
In using the Pimsleur programs how do I check my progress? 

• Complete the lesson units in strict consecutive order -- don't skip around! -- doing no more than one lesson unit per day, although you can repeat the lesson unit for the day. Daily contact with the language is critical to successful learning.
  
• Listen carefully to each lesson unit. Always follow the directions of the instructor.
  
• Speak out loud when directed by the tutor and answer questions within the pauses provided. Do this prior to hearing the confirmation which is provided as reinforcement.
  
• Do all required activities according to instructions, without reference to any outside persons, book, or course.
  

What are the guidelines for success when using the Pimsleur programs?
The simple test for mastery is whether you are able to respond quickly and accurately when your tutor asks a question. If you are responding correctly about eighty percent of the time, then you're ready to proceed to the next lesson. It is important to keep moving forward, but also not to set unreasonable standards of perfection that will keep you from progressing, which is why we recommend using the eighty percent figure as a guide.
You’ll notice that each lesson contains both new and familiar material, so that just when you may be worrying about forgetting something, you will be reminded of it. Another helpful feature of the Pimsleur Language Program is its rate of saturation; you will be responding many times per minute. This saturation enables you to make substantial progress within a short amount of time.
What about regional language differences?
In any large country, and even in many smaller countries, regional differences in language are common. In the United States, for example, a person from Maine can sound very different than someone from Texas. Pronunciations ("accents") vary, and there are also minor differences in vocabulary. For example, what is called a "drinking fountain" in New York or Arizona is known as a "bubbler" in Wisconsin, and a "soft drink" in one part of America will be called a "soda" elsewhere. The differences in English are even more distinct between North Americans and Britons, or between Britons and Australians. But all are native speakers of English; all can communicate with spoken English, read the same newspapers, and watch the same television programs, essentially without difficulty.
Native speakers of a language can often tell where someone is from by listening to him or her speak. In addition to regional differences, there are social differences. Pimsleur Language Programs use a standard “educated” speech, which will generally carry you throughout the country without difficulty.