AI

fine, light

AE

fine, light

AU

now

AW

now

EI

play, say

OE

koi, toy

UI

ruin

CH

Never as in 'church', always as in 'loch' or 'bach' from Scots/German

DH

The voiced 'th' sound as in 'these', or 'those' (not 'thing' or 'thief')

F

Beginning of word; soft as in 'father'. Anywhere else in the word; a 'v' as in 'verge'

HW

The older British English pronunciation of 'white', or with a slight breath before the 'w' as if the letters WH in 'white' were reversed

I

As mentioned above, it becomes a 'y' as in 'yacht' if before a vowel or starting a word

LH

The Welsh LL sound (as in 'llan'). For an approximation, pronounce this as if the letters were reversed and written HL

NG

At the beginning or end of a word, as in the English 'ring' or 'sing', otherwise as in 'finger'

RH

At the beginning of words only: This is what's known as a voiceless trilled R (for a rough guide pronounce it as if the H and trilled R were reversed, it should sound quite breathy with a slight trill)

W

At the end of a word you have two options for pronunciation. The Elves pronounced this like a W in 'woe', 'wight', but this is very difficult for a Man to replicate as you have to be exceptionally careful not to add in a 'schwa' (the vowel sound of the ER in 'butter', 'brother', or the AR in 'wizard').
The schwa sound does not exist in Sindarin.

The Gondorians pronounced a final W like a Sindarin U.
Anywhere else in a word a W should be pronounced as in 'wet' or 'woe'

ER

As in the word 'fair'

Number of syllables in the word

Where the stress falls

Two

On the first syllable (EL-rond, AR-wen)

Three or more

On the penultimate (second to last) syllable (i-SIL-dur, peri-ANN-ath)
or on the third to last syllable (gal-AD-ri-el)