there was a website with load of info on called
http://www.sardiniablock.it/ but it appears to have gone down.
i only went to a couple of places round the north end of the island, which were nice when you're there but i wouldn't travel from the UK specifically for them. people who go to sardina sportclimbing who don't really boulder always mention capo testa as a place with "excellent bouldering", and it is a superb place with amazing rock architecture and climbable rock, but not any really bouldering in the sense that you will want. the north end might not even have the best bouldering (theres stuff all over the island the size of wales) but its a blinging place anyway. most of the rock i climbed on there was a bit crystally and unstable on a small scale, i.e. on big stuff like aretes and cracks it was Ok, but if you tried to use a face hold or crimp a crimp you were pulling shit off, crystalls breakign off under your feet etc.
try google for some more info maybe
if you want general holiday info on the beaches/biatches and accomodation try the lonley planet guide, its very good. we were just staying in the standard expensive tourist hotels. don't let the car hire give you a daewoo (nee chevrolet) matiz, they are shite.
some photos:
