Nz
Like the other guys said, the Kennett Bros book is the Bible for riding in NZ.
here's what I'd recommend for XC/AM type riding on the South island for Park stuff and back country adventure type riding:
Port Hills in Christchurch are great fun with everything from easy XC to full on DH (although most DH trails are 5" bike ride-able)
Hanmer Springs - mix of all level trails, Threshold, yankee Zephyr, Tank, Detox and Big Foot the best.
Kaiteriteri Mtb Park - good fun easy trails, most of the black trails are just fall line and over in 2 seconds so stick with the greeen/blue - berm city and good fun
Nelson - Dun Mtn area, Coppermine Saddle, Old Codgers Mtb Park, Peaking/Sunrise ridge for hard XC/AM
Cannan Down/Rameka Track from Takaka Hill - bit of everything and brilliant riding in varied terrain
Craigieburn - brilliant riding around the ski fields area - Luge, Sidle 73, Hogs Back and Edge trails make abrilliant day out
Croesus near Greymouth/Blackball - technical XC, I've done it 5 ties it's that good
Kirwans near Reefton - massive technical climb (or Heli bike) and mega technical awazing descent - lots of other great rides around Reefton, excellent trails!
Old Ghost Road - from Lyell end or Mokunui end - soon to be an 80km epic ride (with huts) through amazing country, ride from the Lyell side for about 26km up and then descend with a massive smile on your face, same goes for Mokunui end, brilliant benched single track.
Heaphy Track - May to November, multi day adventure ride
Wakamarina - near Blenheim - technical XC
Wharfdale near Christchurch - great Xc, nothing too technical
Queenstown - Gondola, Coronet Peak, 7 Mile, Mike Lake area and everything in between! Awesome riding - get the local map and explore, something for everyone!
Wanaka - like Queenstown but without the steroids - Plantation/Sticky Forest, Deans Bank and lots of great beginner/intermediate stuff all around.
PM me if you'd like specific info on an area I've lived over there and ridden almost everywhere. i'll put some pics up soon from our trip - just got back!
Clint