Hi Koose!
You can find the docs here:
http://www.inivis.com/secondlife.html
Basically, the rules are pretty straight-forward:
1) Make sure you use 100% of the texture space (no holes in your map)
2) Wrap your UVs in both directions (spherical wrapping)
Rule number 2 can be bent with a little LSL script, but this is the default for unscripted sculpties.
Hope that helps!