I was Google-ing and came up with the following information: (check out the last quote in particular)
"Now one thing is clear to the creator of a new language for international use. One of its attributes must be simple spelling. Such a language will be used not only by the common people, by those who can hardly spell their own language. Its orthografy must be simple and regular.
This is a cardinal rule in Esperanto. It is a totally phonetic language, i.e. the same symbol is always used for the same sound. It is also totally phonemic, that is, every word is pronounced just as it is spelt. Consequently there are no silent letters." -
http://www.spellingsociety.org/bulletins/b82/fall/esperanto.php
"Here is the Esperanto alphabet. Each letter always makes the same sound, and spelling is perfectly regular. Click the examples to hear how they're pronounced!" - 'Intro to Esperanto' page on Lernu!
"A foreign student of English could study spelling for a thousand hours and still would not be able to spell as well as a beginner can in Esperanto after a short introductory course. This is because spelling in Esperanto is phonetic. (Esperanto is not at all unique in this. Many other languages are spelled phonetically including Finnish and Swahili.)
Each Esperanto letter represents just one sound. Each Esperanto sound is represented by just one letter." -
http://www.esperanto.ie/english/zaft/zaft(4).htm
"The pronunciation is reminiscent of Spanish or Italian. There are only five vowel sounds, each represented by only one letter and the sounds correspond to the vowels of Spanish and Italian. The 23 consonants present no real problem but English speakers will have to learn to recognize a new letter (accented g) for the j sound, and the letter j is pronounced as a y, etc. However there are no exceptions to the rules so they are easily learned. The consonant sounds are familiar to most westerners, though the letters representing them may be slightly different." -
http://www.micheloud.com/FXM/LA/LA/esperanto.htm
On the above mentioned site, it has the following regarding regional variations:
"One could argue (as some opponents of the language have) that each Esperanto speaker inadvertently adds his own mother tongue accent to Esperanto and thus creates an individual dialect of this intended international language, but if the simple pronunciation rules are adhered to, this does not constitute a problem. One factor which helps to prevent this problem from occurring is that many Esperanto speakers communicate through the internet, which currently remains a written medium, so the accents do not enter into the communication. Speakers of the language do speak it together when meeting, however, and accents do not seem to hinder communication. Look at English for example, English speakers, with exposure, easily learn to understand most non-native attempts at speaking, and this has increased, not diminished, the effectiveness of English."
Regards,
Ben.