is there a dept at the postal service that translates thai addresses into english, or do i have to pay a translation bureau ?

also, what is the best telephone company to go with, and what are the call charges in thailand ?

Ask one of your neighbours, or your landlord to help you write the address. Basically it will be

123/3 Soi 9

Moo 4 (Estate number)

Sukhimvit Road (Thanon is road)

Tambon Surasak (Sub district)

Amphur Munang (District)

Chonburi (Province name)

Postcode

Not every address has an Estate (moo) number,

or a Road name.

There is not much choice on the telephone side.

Either TOT or TT&T, which ever cabled your area.

123/3 Soi 9

i've often wondered why the xxx/yyy format on the address. is it a grid reference or am i been way too optimistic that there is logic to the numberig system?

The first numbers are the land plot number as registered at the land office (1st in 1st out). The number after the slash is the house number (sub number of the registered plot). Am not sure how further division is done but suspect you would have to register as a land plot and then subdivide (probably with higher tax/paperwork charges).

Unfortunately they are almost useless until you find the immediate area as they do not correspond to streets and 123/24 may be next door to 76/47 and next may be 321/1 (although usually not quite that bad).

Like in Japan post office folks have to have experience and knowledge of the area to get the mail to you.

i think houses are numbered as they are built , so a street will have e.g. 4 buildings , nos. 1,2,3 and 4.

until someone comes along and put up another building in the piece of open land between no.3 and no.4 so that may become no 3/1 , or it may become no 5.

so the answer to your question is there may be some logic to the numbering system, but on the other hand there may not.

its better not to dwell on these things.