Just drag your files from the externl drive to the new drive.
Copy the following items from your old drive to the new drive:
In your /Home/ folder: Documents, Movies, Music, Pictures, and Sites folders.
In your /Home/Library/ folder:
/Home/Library/Application Support/AddressBook (copy the whole folder) /Home/Library/Application Support/iCal (copy the whole folder)
Also in /Home/Library/Application Support (copy whatever else you need including folders for any third-party applications)
/Home/Library/Keychains (copy the whole folder) /Home/Library/Mail (copy the whole folder) /Home/Library/Preferences/ (copy the whole folder) /Home /Library/Calendars (copy the whole folder) /Home /Library/iTunes (copy the whole folder) /Home /Library/Safari (copy the whole folder)
If you want cookies:
/Home/Library/Cookies/Cookies.plist /Home/Library/Application Support/WebFoundation/HTTPCookies.plist
For Entourage users:
Entourage is in /Home/Documents/Microsoft User Data Also in /Home/Library/Preferences/Microsoft.
Credit goes to Macjack for this information.
If you need to transfer data for other applications please ask the vendor or ask in the Discussions where specific applications store their data.
5. Once you have transferred what you need restart the new Mac and test to make sure the contents are there for each of the applications.
Reinstall your third-party software.