To get started with Android/Pizzabean, you'll need to get familiar with Git and Repo.
To initialize your local repository using the Pizzabean/CyanogenMod trees, use a command like this:
repo init -u git://github.com/CyanogenMod/android.git -b cm-10.1
mkdir -p .repo/local_manifests
wget https://github.com/shishougang/android/raw/cm-10.1/local_manifest.xml -O .repo/local_manifests/cm_ace.xml
Then to sync up:
repo sync
After sync you can symlink cm_ace.xml from local_manifest/local_manifest.xml to .repo/local_manifests/cm_ace.xml
Please see the CyanogenMod Wiki for building instructions.