The following will be a guide to pronouncing the letters of the Geonosian alphabet: that is, the non-click consonant letters.
All letter guides are equal to English, except below.
A - like father
The letter J is pronounced in a (horn) sound. J is not used in any Geonosian words, except loanwords from other languages (i.e. Jedi, which would theoretically be pronounced (horn)edi, again hypothetical), making the (horn) a relatively rare sound in Geonosian, except when used as audible punctuation.
If any consonant is followed directly by another, as in the word "nvip", the first consonant is pronounced like the English name (i.e. nvip is pronounced like "envipp")
Au - like the interjection "Ow!"
Ee - like in leek
Ey - like the ay in slay
Oe - like in canoe
Oo - like in canoe