The pattern site is
http://www.nsrca.org/
The IMAC (scale aerobatics site) is
http://www.mini-iac.com/main.asp
You can download sequences and judging criteria. The sequences will change the first of every year.
You can obtain the rule book from AMA which was new this year. It has some additional infromation.
Both the above fly sequences (aka "patterns")
The difference is in the type of planes flown.
EXCAP232