Well here's what I play on my acoustic guitar anyhow. It's a four-chord punk song, so 
there's really not too much to it.

A G Bm D

All you do is change the timing for the chorus... just play each chord twice as long.

A[ x02220
G 320003
Bm x24432
D xx0232

If you want the chords they use for ska style it's something like
A xx7655
G xx5433
Bm xx9777
D xx7775

Play with upstrokes and palm muting. It's a tricky rhythm to get down (at least for me) 
but it's a fun one.