Importing masters from iPhoto to Aperture 3 and saving as referenced files on external drive

Question

I'm making the move from iPhoto to Aperture 3.I'm new to Aperture 3 and want o make sure I am importing and saving correctly. So far, I have imported my library of events from iphoto to Aperture 3. I understand that for the most part, it makes sense to house this library on an external drive as "referenced files" vs within Apeture as "managed files." I'm not clear on exactly how to accomplish this set-up. Is this something I should have set-up when doing the initial import or can I move the files now? Once this is done, when importing new files, how do I import to Aperture 3 but save on external drive?
Thanks in advance for your help!

Answer 1

A fabulous answer:
In the olden days ( ) when hobbyists made their own telescopes from kits, everyone wanted a six-inch lens, and the kit makers shipped six-inch lens blanks.  Which the hobbyists used to learn lens grinding.  Which is arduous and requires skill.  Which the hobbyists didn't have until they'd ground that six-inch blank -- an expensive piece of high-quality material at the time -- into a lumpen flawed approximation of a good lens.  Then the hobbyists would contact the kit makers and ask for another lens-blank, so they could build their telescope.  At which point they would drop the project because the six-inch lens blank cost so much.  And much calumny was rained on the kit manufacturers.
Now the kit manufacturers wanted to promote a hobby, and make, in addition to telescope kits, money (not calumny), so they together and separately hit upon the idea of supplying the hobbyist with _two_ lens blanks: a four-inch blank, and a six inch blank.  Nobody wanted a four-inch telescope -- but that's not what the blank was for.  The instructions read (I've shortened this part) "Grind the four-inch blank into the most perfect lens you can.  Check it and re-check it.  Now throw it out.  You likely now have the skill to grind the six-inch blank into a useable lens."
Thus endeth our fable.
The point, of course, is:  start small and gain skill before committing time and material to a task.  Port just a small sub-set of you photos into Aperture.  Experiment with it.  Try different workflows.  Think about how to best use the containers and organization tools Aperture provides.  Develop a long-term naming convention for files and Projects.  Work out a back-up strategy that is scalable and that you will stick with.  My specific recommendation for beginners is: don't worry about Referenced v. Managed at first.  Make all your Masters Managed.  When you have your four-inch Aperture Library all smooth and even, put the entire thing in the system trash -- and then you can start working on an Aperture Library fit for your photos -- one that will allow you to see far, and clear, for years.
Good luck.