No problem… Here is the line from my script which makes the installer package file:
In my case the variable $PACKAGE_FILE is set to pkg/productname-x.x.x.pkg. Of course constant value of the -p switch can be used instead of variable but I run this script in several runs with different values.
The -f switch defines package contents directory (content in my case). And it is the same directory I used earlier when I was working with the GUI version of Package Maker.
The resources directory passed to -r switch contains files to be included to generated installer package. There are three files in this directory: background.jpg, License.txt and Welcome.txt
Info.plist and Description.plist are included to the generated package file too. I have them in different source locations because Description.plist is the same across all versions of the installers while the tmp/Info.plist is generated dynamically based on Info.plist template (I just modify it a bit in few steps earlier in the script to change the bundle version in the template but it’s not very important).
And that’s all - after this line I get the destination package file (.pkg) which is further processed with the hdiutil tool to make a disk image file (.dmg) and uploaded to ftp server 
In any case I paste also the both .plist files. I’m almost sure that I got them from the package made earlier with the GUI version and modified them a little to actual needs.
The Info.plist file:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>CFBundleGetInfoString</key>
<string>1.0.0, My Company Name</string>
<key>CFBundleIdentifier</key>
<string>com.company.productname</string>
<key>CFBundleShortVersionString</key>
<string>1.0.0</string>
<key>IFMajorVersion</key>
<integer>1</integer>
<key>IFMinorVersion</key>
<integer>0</integer>
<key>IFPkgFlagAllowBackRev</key>
<false/>
<key>IFPkgFlagAuthorizationAction</key>
<string>AdminAuthorization</string>
<key>IFPkgFlagBackgroundAlignment</key>
<string>topleft</string>
<key>IFPkgFlagBackgroundScaling</key>
<string>none</string>
<key>IFPkgFlagDefaultLocation</key>
<string>/Library</string>
<key>IFPkgFlagFollowLinks</key>
<true/>
<key>IFPkgFlagInstallFat</key>
<false/>
<key>IFPkgFlagInstalledSize</key>
<integer>18536</integer>
<key>IFPkgFlagIsRequired</key>
<false/>
<key>IFPkgFlagOverwritePermissions</key>
<false/>
<key>IFPkgFlagRelocatable</key>
<false/>
<key>IFPkgFlagRestartAction</key>
<string>NoRestart</string>
<key>IFPkgFlagRootVolumeOnly</key>
<true/>
<key>IFPkgFlagUpdateInstalledLanguages</key>
<false/>
<key>IFPkgFormatVersion</key>
<real>0.10000000149011612</real>
</dict>
</plist>
… and the Description.plist file:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>IFPkgDescriptionDescription</key>
<string>My Great product ;)</string>
<key>IFPkgDescriptionTitle</key>
<string>Product Name</string>
</dict>
</plist>
Hope this helps 
Cheers,
Przemek
