The accent is on the second syllable:
con-CRES-ce-re
As for vowel phonetics, there are numerous variations in pronunciation, and vowels are of course modified by the consonants surrounding them, but here is how I basically pronounce them:
'o' - as in 'bold', but with much less rounding of the lips.
'e' - as in 'let'.
'E' - like 'e' above, but twice as long.
And yes, you are correct with the 'c' always being hard, like the English 'k'. The 'r' is trilled like in Italian, but don't overdo it - two flaps of the tongue on the roof of the mouth should suffice.