To get started with Android/CyanogenMod/SGT7 you'll need to get familiar with Git and Repo.
To initialize your local repository using the CyanogenMod and SGT7 trees, use a command like this:
repo init -u git://github.com/sgt7/android.git -b cm-10.2
Then to sync up:
repo sync
cp android/local_manifest.xml .repo/local_manifests/local_manifest.xml
repo sync
. build/envsetup.sh && brunch model_name
Please see the CyanogenMod Wiki for building instructions.
For more information on this Github Organization and how it is structured, please read the wiki article