When installing the development files for the first time:
unpack site-1.4.8.zip in /Applications/eclipse/dropins after the eclipse installation is moved to Applications.
Create a directory under the user's home directory called "target". Within the "target" directory create a subdirectory called eclipse3.8.2/. Unpack eclipse-3.8.2-delta-pack.zip under ~/target/eclipse3.8.2. This will create 2 new directories called features/ and plugins/.
When installing the development files for the first time: